Merge branch 'task-refactor' into javafx

# Conflicts:
#	HMCL/src/main/java/org/jackhuang/hmcl/ui/LeftPaneController.java
#	HMCL/src/main/java/org/jackhuang/hmcl/ui/account/AccountListItemSkin.java
#	HMCL/src/main/java/org/jackhuang/hmcl/ui/versions/InstallerListPage.java
#	HMCL/src/main/java/org/jackhuang/hmcl/ui/versions/WorldListPage.java
#	HMCL/src/main/java/org/jackhuang/hmcl/upgrade/UpdateHandler.java
#	HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultDependencyManager.java
#	HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultGameBuilder.java
#	HMCLCore/src/main/java/org/jackhuang/hmcl/download/MaintainTask.java
#	HMCLCore/src/main/java/org/jackhuang/hmcl/download/forge/ForgeInstallTask.java
#	HMCLCore/src/main/java/org/jackhuang/hmcl/download/optifine/OptiFineInstallTask.java

HMCL/src/main/java/org/jackhuang/hmcl/game/HMCLModpackExportTask.java

@@ -30,7 +30,7 @@ import java.util.List;
 /**
  * Export the game to a mod pack file.
  */
-public class HMCLModpackExportTask extends Task {
+public class HMCLModpackExportTask extends Task<Void> {
     private final DefaultGameRepository repository;
     private final String version;
     private final List<String> whitelist;

HMCL/src/main/java/org/jackhuang/hmcl/game/HMCLModpackInstallTask.java

@@ -36,13 +36,13 @@ import java.io.IOException;
 import java.util.LinkedList;
 import java.util.List;
 
-public final class HMCLModpackInstallTask extends Task {
+public final class HMCLModpackInstallTask extends Task<Void> {
     private final File zipFile;
     private final String name;
     private final HMCLGameRepository repository;
     private final Modpack modpack;
-    private final List<Task> dependencies = new LinkedList<>();
-    private final List<Task> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
 
     public HMCLModpackInstallTask(Profile profile, File zipFile, Modpack modpack, String name) {
         DependencyManager dependency = profile.getDependency();
@@ -77,12 +77,12 @@ public final class HMCLModpackInstallTask extends Task {
     }
 
     @Override
-    public List<Task> getDependencies() {
+    public List<Task<?>> getDependencies() {
         return dependencies;
     }
 
     @Override
-    public List<Task> getDependents() {
+    public List<Task<?>> getDependents() {
         return dependents;
     }
 

HMCL/src/main/java/org/jackhuang/hmcl/game/LauncherHelper.java

@@ -103,7 +103,7 @@ public final class LauncherHelper {
             try {
                 checkGameState(profile, setting, version, () -> {
                     Controllers.dialog(launchingStepsPane);
-                    Schedulers.newThread().schedule(this::launch0);
+                    Schedulers.newThread().execute(this::launch0);
                 });
             } catch (InterruptedException ignore) {
             }
@@ -122,15 +122,15 @@ public final class LauncherHelper {
         Version version = MaintainTask.maintain(repository.getResolvedVersion(selectedVersion));
         Optional<String> gameVersion = GameVersion.minecraftVersion(repository.getVersionJar(version));
 
-        TaskExecutor executor = Task.of(Schedulers.javafx(), () -> emitStatus(LoadingState.DEPENDENCIES))
-                .then(() -> {
+        TaskExecutor executor = Task.runAsync(Schedulers.javafx(), () -> emitStatus(LoadingState.DEPENDENCIES))
+                .thenCompose(() -> {
                     if (setting.isNotCheckGame())
                         return null;
                     else
                         return dependencyManager.checkGameCompletionAsync(version);
                 })
-                .then(Task.of(Schedulers.javafx(), () -> emitStatus(LoadingState.MODS)))
-                .then(() -> {
+                .thenRun(Schedulers.javafx(), () -> emitStatus(LoadingState.MODS))
+                .thenCompose(() -> {
                     try {
                         ModpackConfiguration<?> configuration = ModpackHelper.readModpackConfiguration(repository.getModpackConfiguration(selectedVersion));
                         if ("Curse".equals(configuration.getType()))
@@ -141,8 +141,8 @@ public final class LauncherHelper {
                         return null;
                     }
                 })
-                .then(Task.of(Schedulers.javafx(), () -> emitStatus(LoadingState.LOGGING_IN)))
-                .thenCompose(() -> Task.ofResult(i18n("account.methods"), () -> {
+                .thenRun(Schedulers.javafx(), () -> emitStatus(LoadingState.LOGGING_IN))
+                .thenSupply(i18n("account.methods"), () -> {
                     try {
                         return account.logIn();
                     } catch (CredentialExpiredException e) {
@@ -152,7 +152,7 @@ public final class LauncherHelper {
                         LOG.warning("Authentication failed, try playing offline: " + e);
                         return account.playOffline().orElseThrow(() -> e);
                     }
-                }))
+                })
                 .thenApply(Schedulers.javafx(), authInfo -> {
                     emitStatus(LoadingState.LAUNCHING);
                     return authInfo;
@@ -164,7 +164,7 @@ public final class LauncherHelper {
                         setting.toLaunchOptions(profile.getGameDir()),
                         launcherVisibility == LauncherVisibility.CLOSE
                                 ? null // Unnecessary to start listening to game process output when close launcher immediately after game launched.
-                                : new HMCLProcessListener(authInfo, setting, gameVersion.isPresent())
+                                : new HMCLProcessListener(authInfo, gameVersion.isPresent())
                 ))
                 .thenCompose(launcher -> { // launcher is prev task's result
                     if (scriptFile == null) {
@@ -200,7 +200,7 @@ public final class LauncherHelper {
             final AtomicInteger finished = new AtomicInteger(0);
 
             @Override
-            public void onFinished(Task task) {
+            public void onFinished(Task<?> task) {
                 finished.incrementAndGet();
                 int runningTasks = executor.getRunningTasks();
                 Platform.runLater(() -> launchingStepsPane.setProgress(1.0 * finished.get() / runningTasks));
@@ -214,7 +214,7 @@ public final class LauncherHelper {
                         // because onStop will be invoked if tasks fail when the executor service shut down.
                         if (!Controllers.isStopped()) {
                             launchingStepsPane.fireEvent(new DialogCloseEvent());
-                            Exception ex = executor.getLastException();
+                            Exception ex = executor.getException();
                             if (ex != null) {
                                 String message;
                                 if (ex instanceof CurseCompletionException) {
@@ -420,7 +420,7 @@ public final class LauncherHelper {
         }
     }
 
-    private static class LaunchTask<T> extends TaskResult<T> {
+    private static class LaunchTask<T> extends Task<T> {
         private final ExceptionalSupplier<T, Exception> supplier;
 
         public LaunchTask(ExceptionalSupplier<T, Exception> supplier) {
@@ -440,7 +440,6 @@ public final class LauncherHelper {
      */
     class HMCLProcessListener implements ProcessListener {
 
-        private final VersionSetting setting;
         private final Map<String, String> forbiddenTokens;
         private ManagedProcess process;
         private boolean lwjgl;
@@ -449,8 +448,7 @@ public final class LauncherHelper {
         private final LinkedList<Pair<String, Log4jLevel>> logs;
         private final CountDownLatch latch = new CountDownLatch(1);
 
-        public HMCLProcessListener(AuthInfo authInfo, VersionSetting setting, boolean detectWindow) {
-            this.setting = setting;
+        public HMCLProcessListener(AuthInfo authInfo, boolean detectWindow) {
             this.detectWindow = detectWindow;
 
             if (authInfo == null)

HMCL/src/main/java/org/jackhuang/hmcl/game/ModpackHelper.java

@@ -86,7 +86,7 @@ public final class ModpackHelper {
             throw new UnsupportedModpackException();
     }
 
-    public static Task getInstallTask(Profile profile, File zipFile, String name, Modpack modpack) {
+    public static Task<Void> getInstallTask(Profile profile, File zipFile, String name, Modpack modpack) {
         profile.getRepository().markVersionAsModpack(name);
 
         ExceptionalRunnable<?> success = () -> {
@@ -117,11 +117,11 @@ public final class ModpackHelper {
         else if (modpack.getManifest() instanceof MultiMCInstanceConfiguration)
             return new MultiMCModpackInstallTask(profile.getDependency(), zipFile, modpack, ((MultiMCInstanceConfiguration) modpack.getManifest()), name)
                     .whenComplete(Schedulers.defaultScheduler(), success, failure)
-                    .then(new MultiMCInstallVersionSettingTask(profile, ((MultiMCInstanceConfiguration) modpack.getManifest()), name));
+                    .thenCompose(new MultiMCInstallVersionSettingTask(profile, ((MultiMCInstanceConfiguration) modpack.getManifest()), name));
         else throw new IllegalStateException("Unrecognized modpack: " + modpack);
     }
 
-    public static Task getUpdateTask(Profile profile, File zipFile, Charset charset, String name, ModpackConfiguration<?> configuration) throws UnsupportedModpackException, MismatchedModpackTypeException {
+    public static Task<Void> getUpdateTask(Profile profile, File zipFile, Charset charset, String name, ModpackConfiguration<?> configuration) throws UnsupportedModpackException, MismatchedModpackTypeException {
         Modpack modpack = ModpackHelper.readModpackManifest(zipFile.toPath(), charset);
 
         switch (configuration.getType()) {

HMCL/src/main/java/org/jackhuang/hmcl/game/MultiMCInstallVersionSettingTask.java

@@ -20,13 +20,12 @@ package org.jackhuang.hmcl.game;
 import org.jackhuang.hmcl.mod.MultiMCInstanceConfiguration;
 import org.jackhuang.hmcl.setting.Profile;
 import org.jackhuang.hmcl.setting.VersionSetting;
-import org.jackhuang.hmcl.task.Scheduler;
 import org.jackhuang.hmcl.task.Schedulers;
 import org.jackhuang.hmcl.task.Task;
 
 import java.util.Objects;
 
-public final class MultiMCInstallVersionSettingTask extends Task {
+public final class MultiMCInstallVersionSettingTask extends Task<Void> {
     private final Profile profile;
     private final MultiMCInstanceConfiguration manifest;
     private final String version;
@@ -35,11 +34,8 @@ public final class MultiMCInstallVersionSettingTask extends Task {
         this.profile = profile;
         this.manifest = manifest;
         this.version = version;
-    }
 
-    @Override
-    public Scheduler getScheduler() {
-        return Schedulers.javafx();
+        setExecutor(Schedulers.javafx());
     }
 
     @Override

HMCL/src/main/java/org/jackhuang/hmcl/setting/Accounts.java

@@ -197,7 +197,7 @@ public final class Accounts {
 
         Account selected = selectedAccount.get();
         if (selected != null) {
-            Schedulers.io().schedule(() -> {
+            Schedulers.io().execute(() -> {
                 try {
                     selected.logIn();
                 } catch (AuthenticationException e) {
@@ -209,7 +209,7 @@ public final class Accounts {
         for (AuthlibInjectorServer server : config().getAuthlibInjectorServers()) {
             if (selected instanceof AuthlibInjectorAccount && ((AuthlibInjectorAccount) selected).getServer() == server)
                 continue;
-            Schedulers.io().schedule(() -> {
+            Schedulers.io().execute(() -> {
                 try {
                     server.fetchMetadataResponse();
                 } catch (IOException e) {

HMCL/src/main/java/org/jackhuang/hmcl/ui/Controllers.java

@@ -208,7 +208,7 @@ public final class Controllers {
             dialog(i18n("launcher.cache_directory.invalid"));
         }
 
-        Task.of(JavaVersion::initialize).start();
+        Task.runAsync(JavaVersion::initialize).start();
 
         scene = new Scene(decorator.getDecorator(), 800, 519);
         scene.getStylesheets().setAll(config().getTheme().getStylesheets());

HMCL/src/main/java/org/jackhuang/hmcl/ui/FXUtils.java

@@ -397,7 +397,7 @@ public final class FXUtils {
      */
     @SuppressWarnings("unchecked")
     @Deprecated
-    public static void bindEnum(JFXComboBox<?> comboBox, Property<? extends Enum> property) {
+    public static void bindEnum(JFXComboBox<?> comboBox, Property<? extends Enum<?>> property) {
         unbindEnum(comboBox);
         ChangeListener<Number> listener = (a, b, newValue) ->
                 ((Property) property).setValue(property.getValue().getClass().getEnumConstants()[newValue.intValue()]);

HMCL/src/main/java/org/jackhuang/hmcl/ui/LeftPaneController.java

@@ -118,10 +118,10 @@ public final class LeftPaneController extends AdvancedListBox {
                 if (repository.getVersionCount() == 0) {
                     File modpackFile = new File("modpack.zip").getAbsoluteFile();
                     if (modpackFile.exists()) {
-                        Task.ofResult(() -> CompressingUtils.findSuitableEncoding(modpackFile.toPath()))
+                        Task.supplyAsync(() -> CompressingUtils.findSuitableEncoding(modpackFile.toPath()))
                                 .thenApply(encoding -> ModpackHelper.readModpackManifest(modpackFile.toPath(), encoding))
                                 .thenApply(modpack -> ModpackHelper.getInstallTask(repository.getProfile(), modpackFile, modpack.getName(), modpack)
-                                            .with(Task.of(Schedulers.javafx(), this::checkAccount)).executor())
+                                            .withRun(Schedulers.javafx(), this::checkAccount).executor())
                                 .thenAccept(Schedulers.javafx(), executor -> {
                                     Controllers.taskDialog(executor, i18n("modpack.installing"));
                                     executor.start();

HMCL/src/main/java/org/jackhuang/hmcl/ui/MainPage.java

@@ -33,7 +33,6 @@ import javafx.scene.control.Label;
 import javafx.scene.layout.HBox;
 import javafx.scene.layout.StackPane;
 import javafx.scene.layout.VBox;
-import javafx.scene.paint.Color;
 import javafx.scene.shape.Rectangle;
 import javafx.util.Duration;
 import org.jackhuang.hmcl.setting.Profile;

HMCL/src/main/java/org/jackhuang/hmcl/ui/account/AccountLoginPane.java

@@ -61,7 +61,7 @@ public class AccountLoginPane extends StackPane {
         String password = txtPassword.getText();
         progressBar.setVisible(true);
         lblCreationWarning.setText("");
-        Task.ofResult(() -> oldAccount.logInWithPassword(password))
+        Task.supplyAsync(() -> oldAccount.logInWithPassword(password))
                 .whenComplete(Schedulers.javafx(), authInfo -> {
                     success.accept(authInfo);
                     fireEvent(new DialogCloseEvent());

HMCL/src/main/java/org/jackhuang/hmcl/ui/account/AddAccountPane.java

@@ -197,7 +197,7 @@ public class AddAccountPane extends StackPane {
         AccountFactory<?> factory = cboType.getSelectionModel().getSelectedItem();
         Object additionalData = getAuthAdditionalData();
 
-        Task.ofResult(() -> factory.create(new Selector(), username, password, additionalData))
+        Task.supplyAsync(() -> factory.create(new Selector(), username, password, additionalData))
                 .whenComplete(Schedulers.javafx(), account -> {
                     int oldIndex = Accounts.getAccounts().indexOf(account);
                     if (oldIndex == -1) {

HMCL/src/main/java/org/jackhuang/hmcl/ui/account/AddAuthlibInjectorServerPane.java

@@ -104,13 +104,13 @@ public class AddAuthlibInjectorServerPane extends StackPane implements DialogAwa
         nextPane.showSpinner();
         addServerPane.setDisable(true);
 
-        Task.of(() -> {
+        Task.runAsync(() -> {
             serverBeingAdded = AuthlibInjectorServer.locateServer(url);
-        }).whenComplete(Schedulers.javafx(), (isDependentSucceeded, exception) -> {
+        }).whenComplete(Schedulers.javafx(), exception -> {
             addServerPane.setDisable(false);
             nextPane.hideSpinner();
 
-            if (isDependentSucceeded) {
+            if (exception == null) {
                 lblServerName.setText(serverBeingAdded.getName());
                 lblServerUrl.setText(serverBeingAdded.getUrl());
 

HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/IconedItem.java

@@ -17,7 +17,6 @@
  */
 package org.jackhuang.hmcl.ui.construct;
 
-import javafx.geometry.Pos;
 import javafx.scene.Node;
 import javafx.scene.control.Label;
 import javafx.scene.layout.HBox;

HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskListPane.java

@@ -42,7 +42,7 @@ import static org.jackhuang.hmcl.util.i18n.I18n.i18n;
 
 public final class TaskListPane extends StackPane {
     private final AdvancedListBox listBox = new AdvancedListBox();
-    private final Map<Task, ProgressListNode> nodes = new HashMap<>();
+    private final Map<Task<?>, ProgressListNode> nodes = new HashMap<>();
     private final ReadOnlyIntegerWrapper finishedTasks = new ReadOnlyIntegerWrapper();
     private final ReadOnlyIntegerWrapper totTasks = new ReadOnlyIntegerWrapper();
 
@@ -72,12 +72,12 @@ public final class TaskListPane extends StackPane {
             }
 
             @Override
-            public void onReady(Task task) {
+            public void onReady(Task<?> task) {
                 Platform.runLater(() -> totTasks.set(totTasks.getValue() + 1));
             }
 
             @Override
-            public void onRunning(Task task) {
+            public void onRunning(Task<?> task) {
                 if (!task.getSignificance().shouldShow())
                     return;
 
@@ -113,7 +113,7 @@ public final class TaskListPane extends StackPane {
             }
 
             @Override
-            public void onFinished(Task task) {
+            public void onFinished(Task<?> task) {
                 ProgressListNode node = nodes.remove(task);
                 if (node == null)
                     return;
@@ -125,7 +125,7 @@ public final class TaskListPane extends StackPane {
             }
 
             @Override
-            public void onFailed(Task task, Throwable throwable) {
+            public void onFailed(Task<?> task, Throwable throwable) {
                 ProgressListNode node = nodes.remove(task);
                 if (node == null)
                     return;
@@ -142,7 +142,7 @@ public final class TaskListPane extends StackPane {
         private final Label title = new Label();
         private final Label state = new Label();
 
-        public ProgressListNode(Task task) {
+        public ProgressListNode(Task<?> task) {
             bar.progressProperty().bind(task.progressProperty());
             title.setText(task.getName());
             state.textProperty().bind(task.messageProperty());

HMCL/src/main/java/org/jackhuang/hmcl/ui/decorator/DecoratorSkin.java

@@ -21,7 +21,6 @@ import com.jfoenix.controls.JFXButton;
 import com.jfoenix.svg.SVGGlyph;
 import javafx.beans.binding.Bindings;
 import javafx.collections.ListChangeListener;
-import javafx.geometry.BoundingBox;
 import javafx.geometry.Bounds;
 import javafx.geometry.Insets;
 import javafx.geometry.Pos;
@@ -56,7 +55,6 @@ public class DecoratorSkin extends SkinBase<Decorator> {
 
     private double xOffset, yOffset, newX, newY, initX, initY;
     private boolean allowMove, isDragging;
-    private BoundingBox originalBox, maximizedBox;
 
     /**
      * Constructor for all SkinBase instances.

HMCL/src/main/java/org/jackhuang/hmcl/ui/download/InstallerWizardProvider.java

@@ -29,7 +29,6 @@ import org.jackhuang.hmcl.game.Version;
 import org.jackhuang.hmcl.setting.Profile;
 import org.jackhuang.hmcl.task.DownloadException;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.ui.Controllers;
 import org.jackhuang.hmcl.ui.construct.MessageDialogPane.MessageType;
 import org.jackhuang.hmcl.ui.wizard.WizardController;
@@ -96,7 +95,7 @@ public final class InstallerWizardProvider implements WizardProvider {
         settings.put("success_message", i18n("install.success"));
         settings.put("failure_callback", (FailureCallback) (settings1, exception, next) -> alertFailureMessage(exception, next));
 
-        TaskResult<Version> ret = Task.ofResult(() -> version);
+        Task<Version> ret = Task.supplyAsync(() -> version);
 
         if (settings.containsKey("forge"))
             ret = ret.thenCompose(profile.getDependency().installLibraryAsync((RemoteVersion) settings.get("forge")));
@@ -107,7 +106,7 @@ public final class InstallerWizardProvider implements WizardProvider {
         if (settings.containsKey("optifine"))
             ret = ret.thenCompose(profile.getDependency().installLibraryAsync((RemoteVersion) settings.get("optifine")));
 
-        return ret.then(profile.getRepository().refreshVersionsAsync());
+        return ret.thenCompose(profile.getRepository().refreshVersionsAsync());
     }
 
     @Override

HMCL/src/main/java/org/jackhuang/hmcl/ui/download/ModpackInstallWizardProvider.java

@@ -71,7 +71,7 @@ public class ModpackInstallWizardProvider implements WizardProvider {
         settings.put(PROFILE, profile);
     }
 
-    private Task finishModpackInstallingAsync(Map<String, Object> settings) {
+    private Task<Void> finishModpackInstallingAsync(Map<String, Object> settings) {
         if (!settings.containsKey(ModpackPage.MODPACK_FILE))
             return null;
 
@@ -93,7 +93,7 @@ public class ModpackInstallWizardProvider implements WizardProvider {
             return null;
         } else {
             return ModpackHelper.getInstallTask(profile, selected, name, modpack)
-                    .then(Task.of(Schedulers.javafx(), () -> profile.setSelectedVersion(name)));
+                    .thenRun(Schedulers.javafx(), () -> profile.setSelectedVersion(name));
         }
     }
 

HMCL/src/main/java/org/jackhuang/hmcl/ui/download/ModpackPage.java

@@ -109,7 +109,7 @@ public final class ModpackPage extends StackPane implements WizardPage {
         }
 
         spinnerPane.showSpinner();
-        Task.ofResult(() -> CompressingUtils.findSuitableEncoding(selectedFile.toPath()))
+        Task.supplyAsync(() -> CompressingUtils.findSuitableEncoding(selectedFile.toPath()))
                 .thenApply(encoding -> manifest = ModpackHelper.readModpackManifest(selectedFile.toPath(), encoding))
                 .whenComplete(Schedulers.javafx(), manifest -> {
                     spinnerPane.hideSpinner();

HMCL/src/main/java/org/jackhuang/hmcl/ui/download/VanillaInstallWizardProvider.java

@@ -43,7 +43,7 @@ public final class VanillaInstallWizardProvider implements WizardProvider {
         settings.put(PROFILE, profile);
     }
 
-    private Task finishVersionDownloadingAsync(Map<String, Object> settings) {
+    private Task<Void> finishVersionDownloadingAsync(Map<String, Object> settings) {
         GameBuilder builder = profile.getDependency().gameBuilder();
 
         String name = (String) settings.get("name");
@@ -59,8 +59,8 @@ public final class VanillaInstallWizardProvider implements WizardProvider {
         if (settings.containsKey("optifine"))
             builder.version((RemoteVersion) settings.get("optifine"));
 
-        return builder.buildAsync().whenComplete((a, b) -> profile.getRepository().refreshVersions())
-                .then(Task.of(Schedulers.javafx(), () -> profile.setSelectedVersion(name)));
+        return builder.buildAsync().whenComplete(any -> profile.getRepository().refreshVersions())
+                .thenRun(Schedulers.javafx(), () -> profile.setSelectedVersion(name));
     }
 
     @Override

HMCL/src/main/java/org/jackhuang/hmcl/ui/download/VersionsPage.java

@@ -128,8 +128,8 @@ public final class VersionsPage extends BorderPane implements WizardPage, Refres
     @Override
     public void refresh() {
         transitionHandler.setContent(spinner, ContainerAnimations.FADE.getAnimationProducer());
-        executor = versionList.refreshAsync(gameVersion, downloadProvider).whenComplete((isDependentSucceeded, exception) -> {
-            if (isDependentSucceeded) {
+        executor = versionList.refreshAsync(gameVersion, downloadProvider).whenComplete(exception -> {
+            if (exception == null) {
                 List<VersionsPageItem> items = loadVersions();
 
                 Platform.runLater(() -> {

HMCL/src/main/java/org/jackhuang/hmcl/ui/export/ExportWizardProvider.java

@@ -60,8 +60,8 @@ public final class ExportWizardProvider implements WizardProvider {
         List<File> launcherJar = Launcher.getCurrentJarFiles();
         boolean includeLauncher = (Boolean) settings.get(ModpackInfoPage.MODPACK_INCLUDE_LAUNCHER) && launcherJar != null;
 
-        return new Task() {
-            Task dependency = null;
+        return new Task<Void>() {
+            Task<?> dependency = null;
 
             @Override
             public void execute() throws Exception {
@@ -80,7 +80,7 @@ public final class ExportWizardProvider implements WizardProvider {
                         ), tempModpack);
 
                 if (includeLauncher) {
-                    dependency = dependency.then(Task.of(() -> {
+                    dependency = dependency.thenRun(() -> {
                         try (Zipper zip = new Zipper(modpackFile.toPath())) {
                             Config exported = new Config();
 
@@ -109,12 +109,12 @@ public final class ExportWizardProvider implements WizardProvider {
                             for (File jar : launcherJar)
                                 zip.putFile(jar, jar.getName());
                         }
-                    }));
+                    });
                 }
             }
 
             @Override
-            public Collection<? extends Task> getDependencies() {
+            public Collection<Task<?>> getDependencies() {
                 return Collections.singleton(dependency);
             }
         };

HMCL/src/main/java/org/jackhuang/hmcl/ui/profile/ProfilePage.java

@@ -26,11 +26,9 @@ import javafx.beans.property.ReadOnlyStringWrapper;
 import javafx.beans.property.SimpleStringProperty;
 import javafx.beans.property.StringProperty;
 import javafx.fxml.FXML;
-import javafx.scene.Node;
 import javafx.scene.layout.StackPane;
 import org.jackhuang.hmcl.setting.Profile;
 import org.jackhuang.hmcl.setting.Profiles;
-import org.jackhuang.hmcl.ui.Controllers;
 import org.jackhuang.hmcl.ui.FXUtils;
 import org.jackhuang.hmcl.ui.construct.FileItem;
 import org.jackhuang.hmcl.ui.construct.PageCloseEvent;
@@ -38,7 +36,6 @@ import org.jackhuang.hmcl.ui.decorator.DecoratorPage;
 import org.jackhuang.hmcl.util.StringUtils;
 
 import java.io.File;
-import java.nio.file.Paths;
 import java.util.Optional;
 
 import static org.jackhuang.hmcl.util.i18n.I18n.i18n;

HMCL/src/main/java/org/jackhuang/hmcl/ui/versions/InstallerListPage.java

@@ -80,9 +80,9 @@ public class InstallerListPage extends ListPageBase<InstallerItem> {
                 LinkedList<Library> newList = new LinkedList<>(version.getLibraries());
                 newList.remove(library);
                 new MaintainTask(version.setLibraries(newList))
-                        .then(maintainedVersion -> new VersionJsonSaveTask(profile.getRepository(), maintainedVersion))
-                        .with(profile.getRepository().refreshVersionsAsync())
-                        .with(Task.of(Schedulers.javafx(), () -> loadVersion(this.profile, this.versionId)))
+                        .thenCompose(maintainedVersion -> new VersionJsonSaveTask(profile.getRepository(), maintainedVersion))
+                        .withCompose(profile.getRepository().refreshVersionsAsync())
+                        .withRun(Schedulers.javafx(), () -> loadVersion(this.profile, this.versionId))
                         .start();
             };
 

HMCL/src/main/java/org/jackhuang/hmcl/ui/versions/ModListPage.java

@@ -86,15 +86,15 @@ public final class ModListPage extends ListPageBase<ModListPageSkin.ModInfoObjec
 
     private void loadMods(ModManager modManager) {
         this.modManager = modManager;
-        Task.ofResult(() -> {
+        Task.supplyAsync(() -> {
             synchronized (ModListPage.this) {
                 runInFX(() -> loadingProperty().set(true));
                 modManager.refreshMods();
                 return new LinkedList<>(modManager.getMods());
             }
-        }).whenComplete(Schedulers.javafx(), (list, isDependentSucceeded, exception) -> {
+        }).whenComplete(Schedulers.javafx(), (list, exception) -> {
             loadingProperty().set(false);
-            if (isDependentSucceeded)
+            if (exception == null)
                 FXUtils.onWeakChangeAndOperate(parentTab.getSelectionModel().selectedItemProperty(), newValue -> {
                     if (newValue != null && newValue.getUserData() == ModListPage.this)
                         itemsProperty().setAll(list.stream().map(ModListPageSkin.ModInfoObject::new).collect(Collectors.toList()));
@@ -112,7 +112,7 @@ public final class ModListPage extends ListPageBase<ModListPageSkin.ModInfoObjec
         List<String> succeeded = new LinkedList<>();
         List<String> failed = new LinkedList<>();
         if (res == null) return;
-        Task.of(() -> {
+        Task.runAsync(() -> {
             for (File file : res) {
                 try {
                     modManager.addMod(file);
@@ -124,7 +124,7 @@ public final class ModListPage extends ListPageBase<ModListPageSkin.ModInfoObjec
                     // Actually addMod will not throw exceptions because FileChooser has already filtered files.
                 }
             }
-        }).with(Task.of(Schedulers.javafx(), () -> {
+        }).withRun(Schedulers.javafx(), () -> {
             List<String> prompt = new LinkedList<>();
             if (!succeeded.isEmpty())
                 prompt.add(i18n("mods.add.success", String.join(", ", succeeded)));
@@ -132,7 +132,7 @@ public final class ModListPage extends ListPageBase<ModListPageSkin.ModInfoObjec
                 prompt.add(i18n("mods.add.failed", String.join(", ", failed)));
             Controllers.dialog(String.join("\n", prompt), i18n("mods.add"));
             loadMods(modManager);
-        })).start();
+        }).start();
     }
 
     public void setParentTab(JFXTabPane parentTab) {

HMCL/src/main/java/org/jackhuang/hmcl/ui/versions/VersionSettingsPage.java

@@ -115,7 +115,7 @@ public final class VersionSettingsPage extends StackPane implements DecoratorPag
 
         FXUtils.smoothScrolling(scroll);
 
-        Task.ofResult(JavaVersion::getJavas).thenAccept(Schedulers.javafx(), list -> {
+        Task.supplyAsync(JavaVersion::getJavas).thenAccept(Schedulers.javafx(), list -> {
             javaItem.loadChildren(list.stream()
                     .map(javaVersion -> javaItem.createChildren(javaVersion.getVersion() + i18n("settings.game.java_directory.bit",
                             javaVersion.getPlatform().getBit()), javaVersion.getBinary().toString(), javaVersion))
@@ -270,7 +270,7 @@ public final class VersionSettingsPage extends StackPane implements DecoratorPag
         VersionSetting versionSetting = lastVersionSetting;
         if (versionSetting == null)
             return;
-        Task.ofResult(versionSetting::getJavaVersion)
+        Task.supplyAsync(versionSetting::getJavaVersion)
                 .thenAccept(Schedulers.javafx(), javaVersion -> javaItem.setSubtitle(Optional.ofNullable(javaVersion)
                         .map(JavaVersion::getBinary).map(Path::toString).orElse("Invalid Java Path")))
                 .start();

HMCL/src/main/java/org/jackhuang/hmcl/ui/versions/Versions.java

@@ -19,7 +19,6 @@ package org.jackhuang.hmcl.ui.versions;
 
 import javafx.stage.FileChooser;
 import org.jackhuang.hmcl.download.game.GameAssetDownloadTask;
-import org.jackhuang.hmcl.download.game.GameAssetIndexDownloadTask;
 import org.jackhuang.hmcl.game.GameRepository;
 import org.jackhuang.hmcl.game.LauncherHelper;
 import org.jackhuang.hmcl.game.Version;

HMCL/src/main/java/org/jackhuang/hmcl/ui/versions/WorldExportPage.java

@@ -74,6 +74,6 @@ public class WorldExportPage extends WizardSinglePage {
 
     @Override
     protected Object finish() {
-        return Task.of(i18n("world.export.wizard", worldName.get()), () -> world.export(Paths.get(path.get()), worldName.get()));
+        return Task.runAsync(i18n("world.export.wizard", worldName.get()), () -> world.export(Paths.get(path.get()), worldName.get()));
     }
 }

HMCL/src/main/java/org/jackhuang/hmcl/ui/versions/WorldListPage.java

@@ -82,12 +82,12 @@ public class WorldListPage extends ListPageBase<WorldListItem> {
 
         setLoading(true);
         Task
-                .of(() -> gameVersion = GameVersion.minecraftVersion(profile.getRepository().getVersionJar(id)).orElse(null))
+                .runAsync(() -> gameVersion = GameVersion.minecraftVersion(profile.getRepository().getVersionJar(id)).orElse(null))
                 .thenSupply(() -> World.getWorlds(savesDir).parallel().collect(Collectors.toList()))
-                .whenComplete(Schedulers.javafx(), (result, isDependentSucceeded, exception) -> {
+                .whenComplete(Schedulers.javafx(), (result, exception) -> {
                     worlds = result;
                     setLoading(false);
-                    if (isDependentSucceeded)
+                    if (exception == null)
                         itemsProperty().setAll(result.stream()
                                 .filter(world -> isShowAll() || world.getGameVersion() == null || world.getGameVersion().equals(gameVersion))
                                 .map(WorldListItem::new).collect(Collectors.toList()));
@@ -107,10 +107,10 @@ public class WorldListPage extends ListPageBase<WorldListItem> {
     private void installWorld(File zipFile) {
         // Only accept one world file because user is required to confirm the new world name
         // Or too many input dialogs are popped.
-        Task.ofResult(() -> new World(zipFile.toPath()))
+        Task.supplyAsync(() -> new World(zipFile.toPath()))
                 .whenComplete(Schedulers.javafx(), world -> {
                     Controllers.inputDialog(i18n("world.name.enter"), (name, resolve, reject) -> {
-                        Task.of(() -> world.install(savesDir, name))
+                        Task.runAsync(() -> world.install(savesDir, name))
                                 .whenComplete(Schedulers.javafx(), () -> {
                                     itemsProperty().add(new WorldListItem(new World(savesDir.resolve(name))));
                                     resolve.run();

HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/AbstractWizardDisplayer.java

@@ -32,8 +32,8 @@ public interface AbstractWizardDisplayer extends WizardDisplayer {
     Queue<Object> getCancelQueue();
 
     @Override
-    default void handleTask(Map<String, Object> settings, Task task) {
-        TaskExecutor executor = task.with(Task.of(Schedulers.javafx(), this::navigateToSuccess)).executor();
+    default void handleTask(Map<String, Object> settings, Task<?> task) {
+        TaskExecutor executor = task.withRun(Schedulers.javafx(), this::navigateToSuccess).executor();
         TaskListPane pane = new TaskListPane();
         pane.setExecutor(executor);
         navigateTo(pane, Navigation.NavigationDirection.FINISH);

HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/DefaultWizardDisplayer.java

@@ -23,7 +23,6 @@ import javafx.fxml.FXML;
 import javafx.scene.Node;
 import javafx.scene.control.Label;
 import javafx.scene.layout.StackPane;
-import org.jackhuang.hmcl.ui.Controllers;
 import org.jackhuang.hmcl.ui.FXUtils;
 import org.jackhuang.hmcl.ui.animation.TransitionHandler;
 import org.jackhuang.hmcl.util.StringUtils;

HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/TaskExecutorDialogWizardDisplayer.java

@@ -35,7 +35,7 @@ import static org.jackhuang.hmcl.util.i18n.I18n.i18n;
 public interface TaskExecutorDialogWizardDisplayer extends AbstractWizardDisplayer {
 
     @Override
-    default void handleTask(Map<String, Object> settings, Task task) {
+    default void handleTask(Map<String, Object> settings, Task<?> task) {
         TaskExecutorDialogPane pane = new TaskExecutorDialogPane(it -> {
             it.fireEvent(new DialogCloseEvent());
             onEnd();
@@ -70,11 +70,11 @@ public interface TaskExecutorDialogWizardDisplayer extends AbstractWizardDisplay
                             else if (!settings.containsKey("forbid_success_message"))
                                 Controllers.dialog(i18n("message.success"), null, MessageType.FINE, () -> onEnd());
                         } else {
-                            if (executor.getLastException() == null)
+                            if (executor.getException() == null)
                                 return;
-                            String appendix = StringUtils.getStackTrace(executor.getLastException());
+                            String appendix = StringUtils.getStackTrace(executor.getException());
                             if (settings.get("failure_callback") instanceof WizardProvider.FailureCallback)
-                                ((WizardProvider.FailureCallback)settings.get("failure_callback")).onFail(settings, executor.getLastException(), () -> onEnd());
+                                ((WizardProvider.FailureCallback)settings.get("failure_callback")).onFail(settings, executor.getException(), () -> onEnd());
                             else if (settings.get("failure_message") instanceof String)
                                 Controllers.dialog(appendix, (String) settings.get("failure_message"), MessageType.ERROR, () -> onEnd());
                             else if (!settings.containsKey("forbid_failure_message"))

HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/WizardController.java

@@ -111,7 +111,7 @@ public class WizardController implements Navigation {
     public void onFinish() {
         Object result = provider.finish(settings);
         if (result instanceof Summary) displayer.navigateTo(((Summary) result).getComponent(), NavigationDirection.NEXT);
-        else if (result instanceof Task) displayer.handleTask(settings, ((Task) result));
+        else if (result instanceof Task<?>) displayer.handleTask(settings, ((Task<?>) result));
         else if (result != null) throw new IllegalStateException("Unrecognized wizard result: " + result);
     }
 

HMCL/src/main/java/org/jackhuang/hmcl/ui/wizard/WizardDisplayer.java

@@ -27,5 +27,5 @@ public interface WizardDisplayer {
     void onEnd();
     void onCancel();
     void navigateTo(Node page, Navigation.NavigationDirection nav);
-    void handleTask(Map<String, Object> settings, Task task);
+    void handleTask(Map<String, Object> settings, Task<?> task);
 }

HMCL/src/main/java/org/jackhuang/hmcl/upgrade/UpdateHandler.java

@@ -20,7 +20,7 @@ package org.jackhuang.hmcl.upgrade;
 import com.google.gson.Gson;
 import com.google.gson.JsonParseException;
 import javafx.application.Platform;
-import javafx.scene.layout.Region;
+
 import org.jackhuang.hmcl.Main;
 import org.jackhuang.hmcl.Metadata;
 import org.jackhuang.hmcl.task.Task;
@@ -101,7 +101,7 @@ public final class UpdateHandler {
                 return;
             }
 
-            Task task = new HMCLDownloadTask(version, downloaded);
+            Task<?> task = new HMCLDownloadTask(version, downloaded);
 
             TaskExecutor executor = task.executor();
             Controllers.taskDialog(executor, i18n("message.downloading"));
@@ -122,7 +122,7 @@ public final class UpdateHandler {
                     }
 
                 } else {
-                    Throwable e = executor.getLastException();
+                    Exception e = executor.getException();
                     LOG.log(Level.WARNING, "Failed to update to " + version, e);
                     Platform.runLater(() -> Controllers.dialog(e.toString(), i18n("update.failed"), MessageType.ERROR));
                 }

HMCLCore/src/main/java/org/jackhuang/hmcl/download/AbstractDependencyManager.java

@@ -17,8 +17,6 @@
  */
 package org.jackhuang.hmcl.download;
 
-import org.jackhuang.hmcl.util.CacheRepository;
-
 /**
  *
  * @author huangyuhui

HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultDependencyManager.java

@@ -26,9 +26,7 @@ import org.jackhuang.hmcl.download.optifine.OptiFineInstallTask;
 import org.jackhuang.hmcl.download.optifine.OptiFineRemoteVersion;
 import org.jackhuang.hmcl.game.DefaultGameRepository;
 import org.jackhuang.hmcl.game.Version;
-import org.jackhuang.hmcl.task.ParallelTask;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.util.function.ExceptionalFunction;
 
 import java.io.IOException;
@@ -72,9 +70,9 @@ public class DefaultDependencyManager extends AbstractDependencyManager {
     }
 
     @Override
-    public Task checkGameCompletionAsync(Version version) {
-        return new ParallelTask(
-                Task.ofThen(() -> {
+    public Task<?> checkGameCompletionAsync(Version version) {
+        return Task.allOf(
+                Task.composeAsync(() -> {
                     if (!repository.getVersionJar(version).exists())
                         return new GameDownloadTask(this, null, version);
                     else
@@ -86,12 +84,12 @@ public class DefaultDependencyManager extends AbstractDependencyManager {
     }
 
     @Override
-    public Task checkLibraryCompletionAsync(Version version) {
+    public Task<?> checkLibraryCompletionAsync(Version version) {
         return new GameLibrariesTask(this, version);
     }
 
     @Override
-    public TaskResult<Version> installLibraryAsync(String gameVersion, Version version, String libraryId, String libraryVersion) {
+    public Task<Version> installLibraryAsync(String gameVersion, Version version, String libraryId, String libraryVersion) {
         VersionList<?> versionList = getVersionList(libraryId);
         return versionList.loadAsync(gameVersion, getDownloadProvider())
                 .thenCompose(() -> installLibraryAsync(version, versionList.getVersion(gameVersion, libraryVersion)
@@ -99,8 +97,8 @@ public class DefaultDependencyManager extends AbstractDependencyManager {
     }
 
     @Override
-    public TaskResult<Version> installLibraryAsync(Version oldVersion, RemoteVersion libraryVersion) {
-        TaskResult<Version> task;
+    public Task<Version> installLibraryAsync(Version oldVersion, RemoteVersion libraryVersion) {
+        Task<Version> task;
         if (libraryVersion instanceof ForgeRemoteVersion)
             task = new ForgeInstallTask(this, oldVersion, (ForgeRemoteVersion) libraryVersion);
         else if (libraryVersion instanceof LiteLoaderRemoteVersion)
@@ -115,7 +113,8 @@ public class DefaultDependencyManager extends AbstractDependencyManager {
                 .thenCompose(newVersion -> new VersionJsonSaveTask(repository, newVersion));
     }
 
-    public ExceptionalFunction<Version, TaskResult<Version>, ?> installLibraryAsync(RemoteVersion libraryVersion) {
+
+    public ExceptionalFunction<Version, Task<Version>, ?> installLibraryAsync(RemoteVersion libraryVersion) {
         return version -> installLibraryAsync(version, libraryVersion);
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultGameBuilder.java

@@ -19,9 +19,7 @@ package org.jackhuang.hmcl.download;
 
 import org.jackhuang.hmcl.download.game.*;
 import org.jackhuang.hmcl.game.Version;
-import org.jackhuang.hmcl.task.ParallelTask;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.util.function.ExceptionalFunction;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 
@@ -48,16 +46,16 @@ public class DefaultGameBuilder extends GameBuilder {
     }
 
     @Override
-    public Task buildAsync() {
+    public Task<?> buildAsync() {
         return new VersionJsonDownloadTask(gameVersion, dependencyManager).thenCompose(rawJson -> {
             Version original = JsonUtils.GSON.fromJson(rawJson, Version.class);
             Version version = original.setId(name).setJar(null);
-            Task vanillaTask = downloadGameAsync(gameVersion, version).then(new ParallelTask(
+            Task<?> vanillaTask = downloadGameAsync(gameVersion, version).thenCompose(Task.allOf(
                     new GameAssetDownloadTask(dependencyManager, version, GameAssetDownloadTask.DOWNLOAD_INDEX_FORCIBLY),
                     new GameLibrariesTask(dependencyManager, version) // Game libraries will be downloaded for multiple times partly, this time is for vanilla libraries.
-            ).with(new VersionJsonSaveTask(dependencyManager.getGameRepository(), version))); // using [with] because download failure here are tolerant.
+            ).withCompose(new VersionJsonSaveTask(dependencyManager.getGameRepository(), version))); // using [with] because download failure here are tolerant.
 
-            TaskResult<Version> libraryTask = vanillaTask.thenSupply(() -> version);
+            Task<Version> libraryTask = vanillaTask.thenSupply(() -> version);
 
             if (toolVersions.containsKey("forge"))
                 libraryTask = libraryTask.thenCompose(libraryTaskHelper(gameVersion, "forge"));
@@ -70,17 +68,17 @@ public class DefaultGameBuilder extends GameBuilder {
                 libraryTask = libraryTask.thenCompose(dependencyManager.installLibraryAsync(remoteVersion));
 
             return libraryTask;
-        }).whenComplete((isDependentSucceeded, exception) -> {
-            if (!isDependentSucceeded)
+        }).whenComplete(exception -> {
+            if (exception != null)
                 dependencyManager.getGameRepository().removeVersionFromDisk(name);
         });
     }
 
-    private ExceptionalFunction<Version, TaskResult<Version>, ?> libraryTaskHelper(String gameVersion, String libraryId) {
+    private ExceptionalFunction<Version, Task<Version>, ?> libraryTaskHelper(String gameVersion, String libraryId) {
         return version -> dependencyManager.installLibraryAsync(gameVersion, version, libraryId, toolVersions.get(libraryId));
     }
 
-    protected Task downloadGameAsync(String gameVersion, Version version) {
+    protected Task<Void> downloadGameAsync(String gameVersion, Version version) {
         return new GameDownloadTask(dependencyManager, gameVersion, version);
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/DependencyManager.java

@@ -46,7 +46,7 @@ public interface DependencyManager {
      *
      * @return the task to check game completion.
      */
-    Task checkGameCompletionAsync(Version version);
+    Task<?> checkGameCompletionAsync(Version version);
 
     /**
      * Check if the game is complete.
@@ -54,7 +54,7 @@ public interface DependencyManager {
      *
      * @return the task to check game completion.
      */
-    Task checkLibraryCompletionAsync(Version version);
+    Task<?> checkLibraryCompletionAsync(Version version);
 
     /**
      * The builder to build a brand new game then libraries such as Forge, LiteLoader and OptiFine.
@@ -71,7 +71,7 @@ public interface DependencyManager {
      * @param libraryVersion the version of being installed library.
      * @return the task to install the specific library.
      */
-    Task installLibraryAsync(String gameVersion, Version version, String libraryId, String libraryVersion);
+    Task<?> installLibraryAsync(String gameVersion, Version version, String libraryId, String libraryVersion);
 
     /**
      * Install a library to a version.
@@ -81,7 +81,7 @@ public interface DependencyManager {
      * @param libraryVersion the remote version of being installed library.
      * @return the task to install the specific library.
      */
-    Task installLibraryAsync(Version version, RemoteVersion libraryVersion);
+    Task<?> installLibraryAsync(Version version, RemoteVersion libraryVersion);
 
     /**
      * Get registered version list.

HMCLCore/src/main/java/org/jackhuang/hmcl/download/GameBuilder.java

@@ -72,5 +72,5 @@ public abstract class GameBuilder {
     /**
      * @return the task that can build thw whole Minecraft environment
      */
-    public abstract Task buildAsync();
+    public abstract Task<?> buildAsync();
 }

HMCLCore/src/main/java/org/jackhuang/hmcl/download/MaintainTask.java

@@ -18,11 +18,10 @@
 package org.jackhuang.hmcl.download;
 
 import org.jackhuang.hmcl.game.*;
-import org.jackhuang.hmcl.task.TaskResult;
-
+import org.jackhuang.hmcl.task.Task;
 import static org.jackhuang.hmcl.download.LibraryAnalyzer.LibraryType.*;
 
-public class MaintainTask extends TaskResult<Version> {
+public class MaintainTask extends Task<Version> {
 
     private final Version version;
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/MojangDownloadProvider.java

@@ -18,7 +18,6 @@
 package org.jackhuang.hmcl.download;
 
 import org.jackhuang.hmcl.download.forge.ForgeBMCLVersionList;
-import org.jackhuang.hmcl.download.forge.ForgeVersionList;
 import org.jackhuang.hmcl.download.game.GameVersionList;
 import org.jackhuang.hmcl.download.liteloader.LiteLoaderVersionList;
 import org.jackhuang.hmcl.download.optifine.OptiFineBMCLVersionList;

HMCLCore/src/main/java/org/jackhuang/hmcl/download/VersionList.java

@@ -62,19 +62,19 @@ public abstract class VersionList<T extends RemoteVersion> {
      * @param downloadProvider DownloadProvider
      * @return the task to reload the remote version list.
      */
-    public abstract Task refreshAsync(DownloadProvider downloadProvider);
+    public abstract Task<?> refreshAsync(DownloadProvider downloadProvider);
 
     /**
      * @param gameVersion the remote version depends on
      * @param downloadProvider DownloadProvider
      * @return the task to reload the remote version list.
      */
-    public Task refreshAsync(String gameVersion, DownloadProvider downloadProvider) {
+    public Task<?> refreshAsync(String gameVersion, DownloadProvider downloadProvider) {
         return refreshAsync(downloadProvider);
     }
 
-    public Task loadAsync(DownloadProvider downloadProvider) {
-        return Task.ofThen(() -> {
+    public Task<?> loadAsync(DownloadProvider downloadProvider) {
+        return Task.composeAsync(() -> {
             lock.readLock().lock();
             boolean loaded;
 
@@ -87,8 +87,8 @@ public abstract class VersionList<T extends RemoteVersion> {
         });
     }
 
-    public Task loadAsync(String gameVersion, DownloadProvider downloadProvider) {
-        return Task.ofThen(() -> {
+    public Task<?> loadAsync(String gameVersion, DownloadProvider downloadProvider) {
+        return Task.composeAsync(() -> {
             lock.readLock().lock();
             boolean loaded;
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/forge/ForgeBMCLVersionList.java

@@ -46,21 +46,21 @@ public final class ForgeBMCLVersionList extends VersionList<ForgeRemoteVersion>
     }
 
     @Override
-    public Task loadAsync(DownloadProvider downloadProvider) {
+    public Task<?> loadAsync(DownloadProvider downloadProvider) {
         throw new UnsupportedOperationException("ForgeBMCLVersionList does not support loading the entire Forge remote version list.");
     }
 
     @Override
-    public Task refreshAsync(DownloadProvider downloadProvider) {
+    public Task<?> refreshAsync(DownloadProvider downloadProvider) {
         throw new UnsupportedOperationException("ForgeBMCLVersionList does not support loading the entire Forge remote version list.");
     }
 
     @Override
-    public Task refreshAsync(String gameVersion, DownloadProvider downloadProvider) {
+    public Task<?> refreshAsync(String gameVersion, DownloadProvider downloadProvider) {
         final GetTask task = new GetTask(NetworkUtils.toURL("https://bmclapi2.bangbang93.com/forge/minecraft/" + gameVersion));
-        return new Task() {
+        return new Task<Void>() {
             @Override
-            public Collection<Task> getDependents() {
+            public Collection<Task<?>> getDependents() {
                 return Collections.singleton(task);
             }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/forge/ForgeInstallTask.java

@@ -23,7 +23,6 @@ import org.jackhuang.hmcl.game.GameVersion;
 import org.jackhuang.hmcl.game.Version;
 import org.jackhuang.hmcl.task.FileDownloadTask;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 import org.jackhuang.hmcl.util.io.CompressingUtils;
 import org.jackhuang.hmcl.util.io.FileUtils;
@@ -43,14 +42,14 @@ import java.util.Optional;
  *
  * @author huangyuhui
  */
-public final class ForgeInstallTask extends TaskResult<Version> {
+public final class ForgeInstallTask extends Task<Version> {
 
     private final DefaultDependencyManager dependencyManager;
     private final Version version;
     private Path installer;
     private final ForgeRemoteVersion remote;
-    private Task dependent;
-    private TaskResult<Version> dependency;
+    private Task<Void> dependent;
+    private Task<Version> dependency;
 
     public ForgeInstallTask(DefaultDependencyManager dependencyManager, Version version, ForgeRemoteVersion remoteVersion) {
         this.dependencyManager = dependencyManager;
@@ -83,12 +82,12 @@ public final class ForgeInstallTask extends TaskResult<Version> {
     }
 
     @Override
-    public Collection<Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return Collections.singleton(dependent);
     }
 
     @Override
-    public Collection<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return Collections.singleton(dependency);
     }
 
@@ -110,7 +109,7 @@ public final class ForgeInstallTask extends TaskResult<Version> {
      * @throws IOException if unable to read compressed content of installer file, or installer file is corrupted, or the installer is not the one we want.
      * @throws VersionMismatchException if required game version of installer does not match the actual one.
      */
-    public static TaskResult<Version> install(DefaultDependencyManager dependencyManager, Version version, Path installer) throws IOException, VersionMismatchException {
+    public static Task<Version> install(DefaultDependencyManager dependencyManager, Version version, Path installer) throws IOException, VersionMismatchException {
         Optional<String> gameVersion = GameVersion.minecraftVersion(dependencyManager.getGameRepository().getVersionJar(version));
         if (!gameVersion.isPresent()) throw new IOException();
         try (FileSystem fs = CompressingUtils.createReadOnlyZipFileSystem(installer)) {

HMCLCore/src/main/java/org/jackhuang/hmcl/download/forge/ForgeNewInstallTask.java

@@ -22,7 +22,6 @@ import org.jackhuang.hmcl.download.game.GameLibrariesTask;
 import org.jackhuang.hmcl.download.optifine.OptiFineInstallTask;
 import org.jackhuang.hmcl.game.*;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.util.StringUtils;
 import org.jackhuang.hmcl.util.function.ExceptionalFunction;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
@@ -50,19 +49,19 @@ import static org.jackhuang.hmcl.util.DigestUtils.digest;
 import static org.jackhuang.hmcl.util.Hex.encodeHex;
 import static org.jackhuang.hmcl.util.Logging.LOG;
 
-public class ForgeNewInstallTask extends TaskResult<Version> {
+public class ForgeNewInstallTask extends Task<Version> {
 
     private final DefaultDependencyManager dependencyManager;
     private final DefaultGameRepository gameRepository;
     private final Version version;
     private final Path installer;
-    private final List<Task> dependents = new LinkedList<>();
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     private ForgeNewInstallProfile profile;
     private Version forgeVersion;
 
-    public ForgeNewInstallTask(DefaultDependencyManager dependencyManager, Version version, Path installer) {
+    ForgeNewInstallTask(DefaultDependencyManager dependencyManager, Version version, Path installer) {
         this.dependencyManager = dependencyManager;
         this.gameRepository = dependencyManager.getGameRepository();
         this.version = version;
@@ -83,12 +82,12 @@ public class ForgeNewInstallTask extends TaskResult<Version> {
     }
 
     @Override
-    public Collection<Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return dependents;
     }
 
     @Override
-    public List<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return dependencies;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/forge/ForgeOldInstallTask.java

@@ -20,7 +20,6 @@ package org.jackhuang.hmcl.download.forge;
 import org.jackhuang.hmcl.download.DefaultDependencyManager;
 import org.jackhuang.hmcl.game.*;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 import org.jackhuang.hmcl.util.io.FileUtils;
 import org.jackhuang.hmcl.util.io.IOUtils;
@@ -31,14 +30,14 @@ import java.util.*;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
-public class ForgeOldInstallTask extends TaskResult<Version> {
+public class ForgeOldInstallTask extends Task<Version> {
 
     private final DefaultDependencyManager dependencyManager;
     private final Version version;
     private final Path installer;
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
-    public ForgeOldInstallTask(DefaultDependencyManager dependencyManager, Version version, Path installer) {
+    ForgeOldInstallTask(DefaultDependencyManager dependencyManager, Version version, Path installer) {
         this.dependencyManager = dependencyManager;
         this.version = version;
         this.installer = installer;
@@ -47,7 +46,7 @@ public class ForgeOldInstallTask extends TaskResult<Version> {
     }
 
     @Override
-    public List<Task> getDependencies() {
+    public List<Task<?>> getDependencies() {
         return dependencies;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/forge/ForgeVersionList.java

@@ -45,12 +45,12 @@ public final class ForgeVersionList extends VersionList<ForgeRemoteVersion> {
     }
 
     @Override
-    public Task refreshAsync(DownloadProvider downloadProvider) {
+    public Task<?> refreshAsync(DownloadProvider downloadProvider) {
         final GetTask task = new GetTask(NetworkUtils.toURL(downloadProvider.injectURL(FORGE_LIST)));
-        return new Task() {
+        return new Task<Void>() {
 
             @Override
-            public Collection<Task> getDependents() {
+            public Collection<Task<?>> getDependents() {
                 return Collections.singleton(task);
             }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/GameAssetDownloadTask.java

@@ -38,14 +38,14 @@ import java.util.List;
  *
  * @author huangyuhui
  */
-public final class GameAssetDownloadTask extends Task {
+public final class GameAssetDownloadTask extends Task<Void> {
     
     private final AbstractDependencyManager dependencyManager;
     private final Version version;
     private final AssetIndexInfo assetIndexInfo;
     private final File assetIndexFile;
-    private final List<Task> dependents = new LinkedList<>();
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     /**
      * Constructor.
@@ -64,12 +64,12 @@ public final class GameAssetDownloadTask extends Task {
     }
 
     @Override
-    public Collection<Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return dependents;
     }
 
     @Override
-    public Collection<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return dependencies;
     }
     

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/GameAssetIndexDownloadTask.java

@@ -22,7 +22,6 @@ import org.jackhuang.hmcl.game.AssetIndexInfo;
 import org.jackhuang.hmcl.game.Version;
 import org.jackhuang.hmcl.task.FileDownloadTask;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.util.CacheRepository;
 import org.jackhuang.hmcl.util.io.NetworkUtils;
 
 import java.io.File;
@@ -34,11 +33,11 @@ import java.util.List;
  *
  * @author huangyuhui
  */
-public final class GameAssetIndexDownloadTask extends Task {
+public final class GameAssetIndexDownloadTask extends Task<Void> {
 
     private final AbstractDependencyManager dependencyManager;
     private final Version version;
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     /**
      * Constructor.
@@ -53,7 +52,7 @@ public final class GameAssetIndexDownloadTask extends Task {
     }
 
     @Override
-    public List<Task> getDependencies() {
+    public List<Task<?>> getDependencies() {
         return dependencies;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/GameDownloadTask.java

@@ -26,6 +26,7 @@ import org.jackhuang.hmcl.util.CacheRepository;
 import org.jackhuang.hmcl.util.io.NetworkUtils;
 
 import java.io.File;
+import java.util.Collection;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -33,11 +34,11 @@ import java.util.List;
  *
  * @author huangyuhui
  */
-public final class GameDownloadTask extends Task {
+public final class GameDownloadTask extends Task<Void> {
     private final DefaultDependencyManager dependencyManager;
     private final String gameVersion;
     private final Version version;
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     public GameDownloadTask(DefaultDependencyManager dependencyManager, String gameVersion, Version version) {
         this.dependencyManager = dependencyManager;
@@ -48,7 +49,7 @@ public final class GameDownloadTask extends Task {
     }
 
     @Override
-    public List<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return dependencies;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/GameLibrariesTask.java

@@ -32,12 +32,12 @@ import java.util.List;
  *
  * @author huangyuhui
  */
-public final class GameLibrariesTask extends Task {
+public final class GameLibrariesTask extends Task<Void> {
 
     private final AbstractDependencyManager dependencyManager;
     private final Version version;
     private final List<Library> libraries;
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     /**
      * Constructor.
@@ -64,7 +64,7 @@ public final class GameLibrariesTask extends Task {
     }
 
     @Override
-    public List<Task> getDependencies() {
+    public List<Task<?>> getDependencies() {
         return dependencies;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/GameVersionList.java

@@ -55,11 +55,11 @@ public final class GameVersionList extends VersionList<GameRemoteVersion> {
     }
 
     @Override
-    public Task refreshAsync(DownloadProvider downloadProvider) {
+    public Task<?> refreshAsync(DownloadProvider downloadProvider) {
         GetTask task = new GetTask(NetworkUtils.toURL(downloadProvider.getVersionListURL()));
-        return new Task() {
+        return new Task<Void>() {
             @Override
-            public Collection<Task> getDependents() {
+            public Collection<Task<?>> getDependents() {
                 return Collections.singleton(task);
             }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/LibrariesUniqueTask.java

@@ -20,7 +20,7 @@ package org.jackhuang.hmcl.download.game;
 import org.jackhuang.hmcl.game.CompatibilityRule;
 import org.jackhuang.hmcl.game.Library;
 import org.jackhuang.hmcl.game.Version;
-import org.jackhuang.hmcl.task.TaskResult;
+import org.jackhuang.hmcl.task.Task;
 import org.jackhuang.hmcl.util.SimpleMultimap;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 import org.jackhuang.hmcl.util.versioning.VersionNumber;
@@ -31,7 +31,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.stream.Collectors;
 
-public class LibrariesUniqueTask extends TaskResult<Version> {
+public class LibrariesUniqueTask extends Task<Version> {
     private final Version version;
 
     public LibrariesUniqueTask(Version version) {

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/LibraryDownloadTask.java

@@ -45,7 +45,7 @@ import java.util.logging.Level;
 import static org.jackhuang.hmcl.util.DigestUtils.digest;
 import static org.jackhuang.hmcl.util.Hex.encodeHex;
 
-public class LibraryDownloadTask extends Task {
+public class LibraryDownloadTask extends Task<Void> {
     private FileDownloadTask task;
     protected final File jar;
     protected final DefaultCacheRepository cacheRepository;
@@ -74,7 +74,7 @@ public class LibraryDownloadTask extends Task {
     }
 
     @Override
-    public Collection<? extends Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         if (cached) return Collections.emptyList();
         else return Collections.singleton(task);
     }
@@ -91,7 +91,7 @@ public class LibraryDownloadTask extends Task {
         if (!isDependentsSucceeded()) {
             // Since FileDownloadTask wraps the actual exception with DownloadException.
             // We should extract it letting the error message clearer.
-            Throwable t = task.getLastException();
+            Exception t = task.getException();
             if (t instanceof DownloadException)
                 throw new LibraryDownloadException(library, t.getCause());
             else

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/VersionJsonDownloadTask.java

@@ -22,7 +22,6 @@ import org.jackhuang.hmcl.download.RemoteVersion;
 import org.jackhuang.hmcl.download.VersionList;
 import org.jackhuang.hmcl.task.GetTask;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.util.io.NetworkUtils;
 
 import java.util.Collection;
@@ -33,11 +32,11 @@ import java.util.List;
  *
  * @author huangyuhui
  */
-public final class VersionJsonDownloadTask extends TaskResult<String> {
+public final class VersionJsonDownloadTask extends Task<String> {
     private final String gameVersion;
     private final DefaultDependencyManager dependencyManager;
-    private final List<Task> dependents = new LinkedList<>();
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
     private final VersionList<?> gameVersionList;
 
     public VersionJsonDownloadTask(String gameVersion, DefaultDependencyManager dependencyManager) {
@@ -52,12 +51,12 @@ public final class VersionJsonDownloadTask extends TaskResult<String> {
     }
 
     @Override
-    public Collection<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return dependencies;
     }
 
     @Override
-    public Collection<Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return dependents;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/game/VersionJsonSaveTask.java

@@ -19,7 +19,7 @@ package org.jackhuang.hmcl.download.game;
 
 import org.jackhuang.hmcl.game.DefaultGameRepository;
 import org.jackhuang.hmcl.game.Version;
-import org.jackhuang.hmcl.task.TaskResult;
+import org.jackhuang.hmcl.task.Task;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 import org.jackhuang.hmcl.util.io.FileUtils;
 
@@ -30,7 +30,7 @@ import java.io.File;
  *
  * @author huangyuhui
  */
-public final class VersionJsonSaveTask extends TaskResult<Version> {
+public final class VersionJsonSaveTask extends Task<Version> {
 
     private final DefaultGameRepository repository;
     private final Version version;

HMCLCore/src/main/java/org/jackhuang/hmcl/download/liteloader/LiteLoaderBMCLVersionList.java

@@ -33,7 +33,6 @@ import javax.xml.parsers.DocumentBuilderFactory;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
-import java.util.Optional;
 
 /**
  *
@@ -52,11 +51,11 @@ public final class LiteLoaderBMCLVersionList extends VersionList<LiteLoaderRemot
     }
 
     @Override
-    public Task refreshAsync(DownloadProvider downloadProvider) {
+    public Task<?> refreshAsync(DownloadProvider downloadProvider) {
         GetTask task = new GetTask(NetworkUtils.toURL(downloadProvider.injectURL(LITELOADER_LIST)));
-        return new Task() {
+        return new Task<Void>() {
             @Override
-            public Collection<Task> getDependents() {
+            public Collection<Task<?>> getDependents() {
                 return Collections.singleton(task);
             }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/liteloader/LiteLoaderInstallTask.java

@@ -23,7 +23,6 @@ import org.jackhuang.hmcl.game.Library;
 import org.jackhuang.hmcl.game.LibraryDownloadInfo;
 import org.jackhuang.hmcl.game.Version;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.util.Lang;
 
 import java.util.Collection;
@@ -36,13 +35,13 @@ import java.util.List;
  *
  * @author huangyuhui
  */
-public final class LiteLoaderInstallTask extends TaskResult<Version> {
+public final class LiteLoaderInstallTask extends Task<Version> {
 
     private final DefaultDependencyManager dependencyManager;
     private final Version version;
     private final LiteLoaderRemoteVersion remote;
-    private final List<Task> dependents = new LinkedList<>();
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     public LiteLoaderInstallTask(DefaultDependencyManager dependencyManager, Version version, LiteLoaderRemoteVersion remoteVersion) {
         this.dependencyManager = dependencyManager;
@@ -51,12 +50,12 @@ public final class LiteLoaderInstallTask extends TaskResult<Version> {
     }
 
     @Override
-    public Collection<Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return dependents;
     }
 
     @Override
-    public Collection<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return dependencies;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/liteloader/LiteLoaderVersionList.java

@@ -33,7 +33,6 @@ import javax.xml.parsers.DocumentBuilderFactory;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Map;
-import java.util.Optional;
 
 /**
  *
@@ -52,11 +51,11 @@ public final class LiteLoaderVersionList extends VersionList<LiteLoaderRemoteVer
     }
 
     @Override
-    public Task refreshAsync(DownloadProvider downloadProvider) {
+    public Task<?> refreshAsync(DownloadProvider downloadProvider) {
         GetTask task = new GetTask(NetworkUtils.toURL(downloadProvider.injectURL(LITELOADER_LIST)));
-        return new Task() {
+        return new Task<Void>() {
             @Override
-            public Collection<Task> getDependents() {
+            public Collection<Task<?>> getDependents() {
                 return Collections.singleton(task);
             }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/optifine/OptiFineBMCLVersionList.java

@@ -46,11 +46,11 @@ public final class OptiFineBMCLVersionList extends VersionList<OptiFineRemoteVer
     }
 
     @Override
-    public Task refreshAsync(DownloadProvider downloadProvider) {
+    public Task<?> refreshAsync(DownloadProvider downloadProvider) {
         GetTask task = new GetTask(NetworkUtils.toURL("http://bmclapi2.bangbang93.com/optifine/versionlist"));
-        return new Task() {
+        return new Task<Void>() {
             @Override
-            public Collection<Task> getDependents() {
+            public Collection<Task<?>> getDependents() {
                 return Collections.singleton(task);
             }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/download/optifine/OptiFineInstallTask.java

@@ -21,7 +21,6 @@ import org.jackhuang.hmcl.download.DefaultDependencyManager;
 import org.jackhuang.hmcl.download.VersionMismatchException;
 import org.jackhuang.hmcl.game.*;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.task.TaskResult;
 import org.jackhuang.hmcl.util.Lang;
 import org.jackhuang.hmcl.util.io.CompressingUtils;
 import org.jackhuang.hmcl.util.io.FileUtils;
@@ -44,14 +43,14 @@ import static org.jackhuang.hmcl.util.Lang.getOrDefault;
  *
  * @author huangyuhui
  */
-public final class OptiFineInstallTask extends TaskResult<Version> {
+public final class OptiFineInstallTask extends Task<Version> {
 
     private final DefaultDependencyManager dependencyManager;
     private final Version version;
     private final OptiFineRemoteVersion remote;
     private final Path installer;
-    private final List<Task> dependents = new LinkedList<>();
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     public OptiFineInstallTask(DefaultDependencyManager dependencyManager, Version version, OptiFineRemoteVersion remoteVersion) {
         this(dependencyManager, version, remoteVersion, null);
@@ -65,12 +64,12 @@ public final class OptiFineInstallTask extends TaskResult<Version> {
     }
 
     @Override
-    public Collection<Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return dependents;
     }
 
     @Override
-    public Collection<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return dependencies;
     }
 
@@ -127,7 +126,7 @@ public final class OptiFineInstallTask extends TaskResult<Version> {
      * @throws IOException if unable to read compressed content of installer file, or installer file is corrupted, or the installer is not the one we want.
      * @throws VersionMismatchException if required game version of installer does not match the actual one.
      */
-    public static TaskResult<Version> install(DefaultDependencyManager dependencyManager, Version version, Path installer) throws IOException, VersionMismatchException {
+    public static Task<Version> install(DefaultDependencyManager dependencyManager, Version version, Path installer) throws IOException, VersionMismatchException {
         File jar = dependencyManager.getGameRepository().getVersionJar(version);
         Optional<String> gameVersion = GameVersion.minecraftVersion(jar);
         if (!gameVersion.isPresent()) throw new IOException();

HMCLCore/src/main/java/org/jackhuang/hmcl/game/GameRepository.java

@@ -77,8 +77,8 @@ public interface GameRepository extends VersionProvider {
      */
     void refreshVersions();
 
-    default Task refreshVersionsAsync() {
-        return Task.of(this::refreshVersions);
+    default Task<Void> refreshVersionsAsync() {
+        return Task.runAsync(this::refreshVersions);
     }
 
     /**

HMCLCore/src/main/java/org/jackhuang/hmcl/game/World.java

@@ -36,7 +36,6 @@ import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.FileSystem;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.logging.Level;
 import java.util.stream.Collectors;

HMCLCore/src/main/java/org/jackhuang/hmcl/mod/CurseCompletionTask.java

@@ -43,14 +43,14 @@ import java.util.stream.Collectors;
  *
  * @author huangyuhui
  */
-public final class CurseCompletionTask extends Task {
+public final class CurseCompletionTask extends Task<Void> {
 
     private final DefaultGameRepository repository;
     private final ModManager modManager;
     private final String version;
     private CurseManifest manifest = null;
-    private final List<Task> dependents = new LinkedList<>();
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     /**
      * Constructor.
@@ -86,12 +86,12 @@ public final class CurseCompletionTask extends Task {
     }
 
     @Override
-    public Collection<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return dependencies;
     }
 
     @Override
-    public Collection<Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return dependents;
     }
 
@@ -147,7 +147,7 @@ public final class CurseCompletionTask extends Task {
         // Let this task fail if the curse manifest has not been completed.
         // But continue other downloads.
         if (!flag.get() || notFound.get())
-            dependencies.add(Task.of(() -> {
+            dependencies.add(Task.runAsync(() -> {
                 if (notFound.get())
                     throw new CurseCompletionException(new FileNotFoundException());
                 else

HMCLCore/src/main/java/org/jackhuang/hmcl/mod/CurseInstallTask.java

@@ -38,7 +38,7 @@ import java.util.List;
  *
  * @author huangyuhui
  */
-public final class CurseInstallTask extends Task {
+public final class CurseInstallTask extends Task<Void> {
 
     private final DefaultDependencyManager dependencyManager;
     private final DefaultGameRepository repository;
@@ -48,8 +48,8 @@ public final class CurseInstallTask extends Task {
     private final String name;
     private final File run;
     private final ModpackConfiguration<CurseManifest> config;
-    private final List<Task> dependents = new LinkedList<>();
-    private final List<Task> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
 
     /**
      * Constructor.
@@ -99,12 +99,12 @@ public final class CurseInstallTask extends Task {
     }
 
     @Override
-    public Collection<Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return dependents;
     }
 
     @Override
-    public Collection<Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return dependencies;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/mod/MinecraftInstanceTask.java

@@ -33,7 +33,7 @@ import java.util.List;
 import static org.jackhuang.hmcl.util.DigestUtils.digest;
 import static org.jackhuang.hmcl.util.Hex.encodeHex;
 
-public final class MinecraftInstanceTask<T> extends Task {
+public final class MinecraftInstanceTask<T> extends Task<Void> {
 
     private final File zipFile;
     private final Charset encoding;

HMCLCore/src/main/java/org/jackhuang/hmcl/mod/ModpackInstallTask.java

@@ -31,7 +31,7 @@ import java.util.function.Predicate;
 import static org.jackhuang.hmcl.util.DigestUtils.digest;
 import static org.jackhuang.hmcl.util.Hex.encodeHex;
 
-public class ModpackInstallTask<T> extends Task {
+public class ModpackInstallTask<T> extends Task<Void> {
 
     private final File modpackFile;
     private final File dest;

HMCLCore/src/main/java/org/jackhuang/hmcl/mod/ModpackUpdateTask.java

@@ -26,14 +26,14 @@ import java.nio.file.Path;
 import java.util.Collection;
 import java.util.Collections;
 
-public class ModpackUpdateTask extends Task {
+public class ModpackUpdateTask extends Task<Void> {
 
     private final DefaultGameRepository repository;
     private final String id;
-    private final Task updateTask;
+    private final Task<?> updateTask;
     private final Path backupFolder;
 
-    public ModpackUpdateTask(DefaultGameRepository repository, String id, Task updateTask) {
+    public ModpackUpdateTask(DefaultGameRepository repository, String id, Task<?> updateTask) {
         this.repository = repository;
         this.id = id;
         this.updateTask = updateTask;
@@ -49,7 +49,7 @@ public class ModpackUpdateTask extends Task {
     }
 
     @Override
-    public Collection<? extends Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return Collections.singleton(updateTask);
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/mod/MultiMCModpackInstallTask.java

@@ -46,15 +46,15 @@ import java.util.Optional;
  *
  * @author huangyuhui
  */
-public final class MultiMCModpackInstallTask extends Task {
+public final class MultiMCModpackInstallTask extends Task<Void> {
 
     private final File zipFile;
     private final Modpack modpack;
     private final MultiMCInstanceConfiguration manifest;
     private final String name;
     private final DefaultGameRepository repository;
-    private final List<Task> dependencies = new LinkedList<>();
-    private final List<Task> dependents = new LinkedList<>();
+    private final List<Task<?>> dependencies = new LinkedList<>();
+    private final List<Task<?>> dependents = new LinkedList<>();
     
     public MultiMCModpackInstallTask(DefaultDependencyManager dependencyManager, File zipFile, Modpack modpack, MultiMCInstanceConfiguration manifest, String name) {
         this.zipFile = zipFile;
@@ -91,7 +91,7 @@ public final class MultiMCModpackInstallTask extends Task {
     }
     
     @Override
-    public List<Task> getDependencies() {
+    public List<Task<?>> getDependencies() {
         return dependencies;
     }
 
@@ -126,7 +126,7 @@ public final class MultiMCModpackInstallTask extends Task {
     }
 
     @Override
-    public List<Task> getDependents() {
+    public List<Task<?>> getDependents() {
         return dependents;
     }
     

HMCLCore/src/main/java/org/jackhuang/hmcl/task/CoupleTask.java

@@ -1,74 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.task;
-
-import org.jackhuang.hmcl.util.AutoTypingMap;
-import org.jackhuang.hmcl.util.function.ExceptionalSupplier;
-
-import java.util.Collection;
-import java.util.Collections;
-
-/**
- * A task that combines two tasks and make sure [pred] runs before succ.
- *
- * @author huangyuhui
- */
-final class CoupleTask extends Task {
-
-    private final boolean relyingOnDependents;
-    private final Task pred;
-    private Task succ;
-    private final ExceptionalSupplier<Task, ?> supplier;
-
-    /**
-     * A task that combines two tasks and make sure pred runs before succ.
-     *
-     * @param pred the task that runs before supplier.
-     * @param supplier a callback that returns the task runs after pred, succ will be executed asynchronously. You can do something that relies on the result of pred.
-     * @param relyingOnDependents true if this task chain will be broken when task pred fails.
-     */
-    CoupleTask(Task pred, ExceptionalSupplier<Task, ?> supplier, boolean relyingOnDependents) {
-        this.pred = pred;
-        this.supplier = supplier;
-        this.relyingOnDependents = relyingOnDependents;
-
-        setSignificance(TaskSignificance.MODERATE);
-        setName(supplier.toString());
-    }
-
-    @Override
-    public void execute() throws Exception {
-        setName(supplier.toString());
-        succ = supplier.get();
-    }
-
-    @Override
-    public Collection<Task> getDependents() {
-        return pred == null ? Collections.emptySet() : Collections.singleton(pred);
-    }
-
-    @Override
-    public Collection<Task> getDependencies() {
-        return succ == null ? Collections.emptySet() : Collections.singleton(succ);
-    }
-
-    @Override
-    public boolean isRelyingOnDependents() {
-        return relyingOnDependents;
-    }
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/task/FileDownloadTask.java

@@ -34,6 +34,7 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.security.MessageDigest;
 import java.util.Optional;
+import java.util.concurrent.Executor;
 import java.util.logging.Level;
 
 import static java.util.Objects.requireNonNull;
@@ -44,7 +45,7 @@ import static org.jackhuang.hmcl.util.DigestUtils.getDigest;
  *
  * @author huangyuhui
  */
-public class FileDownloadTask extends Task {
+public class FileDownloadTask extends Task<Void> {
 
     public static class IntegrityCheck {
         private String algorithm;
@@ -121,6 +122,7 @@ public class FileDownloadTask extends Task {
         this.retry = retry;
 
         setName(file.getName());
+        setExecutor(Schedulers.io());
     }
 
     private void closeFiles() {
@@ -142,11 +144,6 @@ public class FileDownloadTask extends Task {
         stream = null;
     }
 
-    @Override
-    public Scheduler getScheduler() {
-        return Schedulers.io();
-    }
-
     public EventManager<FailedEvent<URL>> getOnFailed() {
         return onFailed;
     }

HMCLCore/src/main/java/org/jackhuang/hmcl/task/GetTask.java

@@ -30,46 +30,37 @@ import java.net.HttpURLConnection;
 import java.net.URL;
 import java.nio.charset.Charset;
 import java.nio.file.Path;
+import java.util.concurrent.Executor;
 import java.util.logging.Level;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 
 /**
  *
- * @author huang
+ * @author huangyuhui
  */
-public final class GetTask extends TaskResult<String> {
+public final class GetTask extends Task<String> {
 
     private final URL url;
     private final Charset charset;
     private final int retry;
-    private final String id;
     private CacheRepository repository = CacheRepository.getInstance();
 
     public GetTask(URL url) {
-        this(url, ID);
+        this(url, UTF_8);
     }
 
-    public GetTask(URL url, String id) {
-        this(url, id, UTF_8);
+    public GetTask(URL url, Charset charset) {
+        this(url, charset, 5);
     }
 
-    public GetTask(URL url, String id, Charset charset) {
-        this(url, id, charset, 5);
-    }
-
-    public GetTask(URL url, String id, Charset charset, int retry) {
+    public GetTask(URL url, Charset charset, int retry) {
         this.url = url;
         this.charset = charset;
         this.retry = retry;
-        this.id = id;
 
         setName(url.toString());
-    }
-
-    @Override
-    public Scheduler getScheduler() {
-        return Schedulers.io();
+        setExecutor(Schedulers.io());
     }
 
     public GetTask setCacheRepository(CacheRepository repository) {
@@ -138,9 +129,4 @@ public final class GetTask extends TaskResult<String> {
             throw new DownloadException(url, exception);
     }
 
-    /**
-     * The default task result ID.
-     */
-    public static final String ID = "http_get";
-
 }

HMCLCore/src/main/java/org/jackhuang/hmcl/task/ParallelTask.java

@@ -1,57 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.task;
-
-import java.util.Arrays;
-import java.util.Collection;
-
-/**
- * The tasks that provides a way to execute tasks parallelly.
- * Fails when some of {@link #tasks} failed.
- *
- * @author huangyuhui
- */
-public final class ParallelTask extends Task {
-
-    private final Collection<Task> tasks;
-
-    /**
-     * Constructor.
-     *
-     * @param tasks the tasks that can be executed parallelly.
-     */
-    public ParallelTask(Task... tasks) {
-        this.tasks = Arrays.asList(tasks);
-        setSignificance(TaskSignificance.MINOR);
-    }
-
-    public ParallelTask(Collection<Task> tasks) {
-        this.tasks = tasks;
-        setSignificance(TaskSignificance.MINOR);
-    }
-
-    @Override
-    public void execute() {
-    }
-
-    @Override
-    public Collection<Task> getDependents() {
-        return tasks;
-    }
-
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/task/Scheduler.java

@@ -1,38 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.task;
-
-import java.util.concurrent.Future;
-
-import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
-
-/**
- * Determines how a task is executed.
- *
- * @author huangyuhui
- */
-public abstract class Scheduler {
-
-    /**
-     * Schedules the given task.
-     *
-     * @return the future
-     */
-    public abstract Future<?> schedule(ExceptionalRunnable<?> block);
-
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/task/SchedulerExecutorService.java

@@ -1,45 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.task;
-
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Future;
-
-import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
-
-/**
- *
- * @author huangyuhui
- */
-class SchedulerExecutorService extends Scheduler {
-
-    private final ExecutorService executorService;
-
-    public SchedulerExecutorService(ExecutorService executorService) {
-        this.executorService = executorService;
-    }
-
-    @Override
-    public Future<?> schedule(ExceptionalRunnable<?> block) {
-        if (executorService.isShutdown() || executorService.isTerminated())
-            return Schedulers.NONE.schedule(block);
-        else
-            return executorService.submit(block.toCallable());
-    }
-
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/task/SchedulerImpl.java

@@ -1,92 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.task;
-
-import java.util.concurrent.*;
-import java.util.concurrent.atomic.AtomicReference;
-import java.util.function.Consumer;
-
-import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
-
-/**
- *
- * @author huangyuhui
- */
-class SchedulerImpl extends Scheduler {
-
-    private final Consumer<Runnable> executor;
-
-    public SchedulerImpl(Consumer<Runnable> executor) {
-        this.executor = executor;
-    }
-
-    @Override
-    public Future<?> schedule(ExceptionalRunnable<?> block) {
-        CountDownLatch latch = new CountDownLatch(1);
-        AtomicReference<Exception> wrapper = new AtomicReference<>();
-
-        executor.accept(() -> {
-            try {
-                block.run();
-            } catch (Exception e) {
-                wrapper.set(e);
-            } finally {
-                latch.countDown();
-            }
-            Thread.interrupted(); // clear the `interrupted` flag to prevent from interrupting EventDispatch thread.
-        });
-
-        return new Future<Void>() {
-            @Override
-            public boolean cancel(boolean mayInterruptIfRunning) {
-                return false;
-            }
-
-            @Override
-            public boolean isCancelled() {
-                return false;
-            }
-
-            @Override
-            public boolean isDone() {
-                return latch.getCount() == 0;
-            }
-
-            private Void getImpl() throws ExecutionException {
-                Exception e = wrapper.get();
-                if (e != null)
-                    throw new ExecutionException(e);
-                return null;
-            }
-
-            @Override
-            public Void get() throws InterruptedException, ExecutionException {
-                latch.await();
-                return getImpl();
-            }
-
-            @Override
-            public Void get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
-                if (!latch.await(timeout, unit))
-                    throw new TimeoutException();
-                return getImpl();
-            }
-        };
-    }
-
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/task/Schedulers.java

@@ -17,8 +17,10 @@
  */
 package org.jackhuang.hmcl.task;
 
+import javafx.application.Platform;
 import org.jackhuang.hmcl.util.Logging;
 
+import javax.swing.*;
 import java.util.concurrent.*;
 
 /**
@@ -32,7 +34,7 @@ public final class Schedulers {
 
     private static volatile ExecutorService CACHED_EXECUTOR;
 
-    private static synchronized ExecutorService getCachedExecutorService() {
+    public static synchronized Executor newThread() {
         if (CACHED_EXECUTOR == null)
             CACHED_EXECUTOR = new ThreadPoolExecutor(0, Integer.MAX_VALUE,
                     60, TimeUnit.SECONDS, new SynchronousQueue<>(), Executors.defaultThreadFactory());
@@ -42,7 +44,7 @@ public final class Schedulers {
 
     private static volatile ExecutorService IO_EXECUTOR;
 
-    private static synchronized ExecutorService getIOExecutorService() {
+    public static synchronized Executor io() {
         if (IO_EXECUTOR == null)
             IO_EXECUTOR = Executors.newFixedThreadPool(6, runnable -> {
                 Thread thread = Executors.defaultThreadFactory().newThread(runnable);
@@ -55,7 +57,7 @@ public final class Schedulers {
 
     private static volatile ExecutorService SINGLE_EXECUTOR;
 
-    private static synchronized ExecutorService getSingleExecutorService() {
+    public static synchronized Executor computation() {
         if (SINGLE_EXECUTOR == null)
             SINGLE_EXECUTOR = Executors.newSingleThreadExecutor(runnable -> {
                 Thread thread = Executors.defaultThreadFactory().newThread(runnable);
@@ -66,54 +68,18 @@ public final class Schedulers {
         return SINGLE_EXECUTOR;
     }
 
-    private static final Scheduler IMMEDIATE = new SchedulerImpl(Runnable::run);
-
-    public static Scheduler immediate() {
-        return IMMEDIATE;
+    public static Executor javafx() {
+        return Platform::runLater;
     }
 
-    private static Scheduler NEW_THREAD;
-
-    public static synchronized Scheduler newThread() {
-        if (NEW_THREAD == null)
-            NEW_THREAD = new SchedulerExecutorService(getCachedExecutorService());
-        return NEW_THREAD;
+    public static Executor swing() {
+        return SwingUtilities::invokeLater;
     }
 
-    private static Scheduler IO;
-
-    public static synchronized Scheduler io() {
-        if (IO == null)
-            IO = new SchedulerExecutorService(getIOExecutorService());
-        return IO;
-    }
-
-    private static Scheduler COMPUTATION;
-
-    public static synchronized Scheduler computation() {
-        if (COMPUTATION == null)
-            COMPUTATION = new SchedulerExecutorService(getSingleExecutorService());
-        return COMPUTATION;
-    }
-
-    private static final Scheduler JAVAFX = new SchedulerImpl(javafx.application.Platform::runLater);
-
-    public static Scheduler javafx() {
-        return JAVAFX;
-    }
-
-    private static final Scheduler SWING = new SchedulerImpl(javax.swing.SwingUtilities::invokeLater);
-
-    public static Scheduler swing() {
-        return SWING;
-    }
-
-    public static synchronized Scheduler defaultScheduler() {
+    public static Executor defaultScheduler() {
         return newThread();
     }
 
-    static final Scheduler NONE = new SchedulerImpl(any -> {});
-
     public static synchronized void shutdown() {
         Logging.LOG.info("Shutting down executor services.");
 

HMCLCore/src/main/java/org/jackhuang/hmcl/task/SimpleTask.java

@@ -1,52 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.task;
-
-import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
-
-/**
- *
- * @author huangyuhui
- */
-class SimpleTask extends Task {
-
-    private final ExceptionalRunnable<?> closure;
-    private final Scheduler scheduler;
-
-    public SimpleTask(String name, ExceptionalRunnable<?> closure, Scheduler scheduler) {
-        this.closure = closure;
-        this.scheduler = scheduler;
-
-        if (name == null) {
-            setSignificance(TaskSignificance.MINOR);
-            setName(closure.toString());
-        } else {
-            setName(name);
-        }
-    }
-
-    @Override
-    public Scheduler getScheduler() {
-        return scheduler;
-    }
-
-    @Override
-    public void execute() throws Exception {
-        closure.run();
-    }
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/task/SimpleTaskResult.java

@@ -1,46 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.task;
-
-import org.jackhuang.hmcl.util.AutoTypingMap;
-import org.jackhuang.hmcl.util.function.ExceptionalFunction;
-import org.jackhuang.hmcl.util.function.ExceptionalSupplier;
-
-import java.util.concurrent.Callable;
-
-/**
- *
- * @author huangyuhui
- */
-class SimpleTaskResult<V> extends TaskResult<V> {
-
-    private final Callable<V> callable;
-
-    public SimpleTaskResult(Callable<V> callable) {
-        this.callable = callable;
-    }
-
-    public SimpleTaskResult(ExceptionalSupplier<V, ?> supplier) {
-        this.callable = supplier.toCallable();
-    }
-
-    @Override
-    public void execute() throws Exception {
-        setResult(callable.call());
-    }
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/task/Task.java

@@ -27,13 +27,17 @@ import org.jackhuang.hmcl.util.InvocationDispatcher;
 import org.jackhuang.hmcl.util.Logging;
 import org.jackhuang.hmcl.util.ReflectionHelper;
 import org.jackhuang.hmcl.util.function.ExceptionalConsumer;
+import org.jackhuang.hmcl.util.function.ExceptionalFunction;
 import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
 import org.jackhuang.hmcl.util.function.ExceptionalSupplier;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.concurrent.Callable;
 import java.util.concurrent.CancellationException;
+import java.util.concurrent.Executor;
+import java.util.function.Consumer;
 import java.util.logging.Level;
 
 /**
@@ -41,50 +45,65 @@ import java.util.logging.Level;
  *
  * @author huangyuhui
  */
-public abstract class Task {
+public abstract class Task<T> {
 
     private final EventManager<TaskEvent> onDone = new EventManager<>();
 
-    private TaskSignificance significance = TaskSignificance.MAJOR;
-
     /**
      * True if not logging when executing this task.
      */
+    private TaskSignificance significance = TaskSignificance.MAJOR;
+
     public final TaskSignificance getSignificance() {
         return significance;
     }
 
-    public void setSignificance(TaskSignificance significance) {
+    public final void setSignificance(TaskSignificance significance) {
         this.significance = significance;
     }
 
+    // state
     private TaskState state = TaskState.READY;
 
-    public TaskState getState() {
+    public final TaskState getState() {
         return state;
     }
 
-    void setState(TaskState state) {
+    final void setState(TaskState state) {
         this.state = state;
     }
 
-    private Exception lastException;
-
-    public Exception getLastException() {
-        return lastException;
-    }
-
-    void setLastException(Exception e) {
-        lastException = e;
-    }
+    // last exception
+    private Exception exception;
 
     /**
-     * The scheduler that decides how this task runs.
+     * When task has been cancelled, task.exception will be null.
+     *
+     * @return the exception thrown during execution, possibly from dependents or dependencies.
      */
-    public Scheduler getScheduler() {
-        return Schedulers.defaultScheduler();
+    public final Exception getException() {
+        return exception;
     }
 
+    final void setException(Exception e) {
+        exception = e;
+    }
+
+    private Executor executor = Schedulers.defaultScheduler();
+
+    /**
+     * The executor that decides how this task runs.
+     */
+    public final Executor getExecutor() {
+        return executor;
+    }
+
+    public final Task<T> setExecutor(Executor executor) {
+        this.executor = executor;
+        return this;
+    }
+
+    // dependents succeeded
     private boolean dependentsSucceeded = false;
 
     public boolean isDependentsSucceeded() {
@@ -95,6 +114,7 @@ public abstract class Task {
         dependentsSucceeded = true;
     }
 
+    // dependencies succeeded
     private boolean dependenciesSucceeded = false;
 
     public boolean isDependenciesSucceeded() {
@@ -123,17 +143,57 @@ public abstract class Task {
         return true;
     }
 
+    // name
     private String name = getClass().getName();
 
     public String getName() {
         return name;
     }
 
-    public Task setName(String name) {
+    public Task<T> setName(String name) {
         this.name = name;
         return this;
     }
 
+    @Override
+    public String toString() {
+        if (getClass().getName().equals(getName()))
+            return getName();
+        else
+            return getClass().getName() + "[" + getName() + "]";
+    }
+
+    // result
+    private T result;
+    private Consumer<T> resultConsumer;
+
+    /**
+     * Returns the result of this task.
+     *
+     * The result will be generated only if the execution is completed.
+     */
+    public T getResult() {
+        return result;
+    }
+
+    protected void setResult(T result) {
+        this.result = result;
+        if (resultConsumer != null)
+            resultConsumer.accept(result);
+    }
+
+    /**
+     * Sync the result of this task by given action.
+     *
+     * @param action the action to perform when result of this task changed
+     * @return this Task
+     */
+    public Task<T> storeTo(Consumer<T> action) {
+        this.resultConsumer = action;
+        return this;
+    }
+
+    // execution
     public boolean doPreExecute() {
         return false;
     }
@@ -171,7 +231,7 @@ public abstract class Task {
     /**
      * The collection of sub-tasks that should execute **before** this task running.
      */
-    public Collection<? extends Task> getDependents() {
+    public Collection<Task<?>> getDependents() {
         return Collections.emptySet();
     }
 
@@ -179,7 +239,7 @@ public abstract class Task {
      * The collection of sub-tasks that should execute **after** this task running.
      * Will not be executed if execution fails.
      */
-    public Collection<? extends Task> getDependencies() {
+    public Collection<Task<?>> getDependencies() {
         return Collections.emptySet();
     }
 
@@ -232,15 +292,15 @@ public abstract class Task {
         if (getSignificance().shouldLog())
             Logging.LOG.log(Level.FINE, "Executing task: " + getName());
 
-        for (Task task : getDependents())
+        for (Task<?> task : getDependents())
             doSubTask(task);
         execute();
-        for (Task task : getDependencies())
+        for (Task<?> task : getDependencies())
             doSubTask(task);
         onDone.fireEvent(new TaskEvent(this, this, false));
     }
 
-    private void doSubTask(Task task) throws Exception {
+    private void doSubTask(Task<?> task) throws Exception {
         message.bind(task.message);
         progress.bind(task.progress);
         task.run();
@@ -273,61 +333,240 @@ public abstract class Task {
         return executor().test();
     }
 
-    public final Task then(Task b) {
-        return then(convert(b));
-    }
-
-    public final Task then(ExceptionalSupplier<Task, ?> b) {
-        return new CoupleTask(this, b, true);
-    }
-
     /**
-     * Returns a new TaskResult that, when this task completes
-     * normally, is executed using the default Scheduler.
+     * Returns a new Task that, when this task completes
+     * normally, is executed using the default Executor, with this
+     * task's result as the argument to the supplied function.
      *
-     * @param fn the function to use to compute the value of the returned TaskResult
+     * @param fn the function to use to compute the value of the returned Task
      * @param <U> the function's return type
-     * @return the new TaskResult
+     * @return the new Task
      */
-    public final <U> TaskResult<U> thenSupply(Callable<U> fn) {
-        return thenCompose(() -> Task.ofResult(fn));
+    public <U, E extends Exception> Task<U> thenApply(ExceptionalFunction<T, U, E> fn) {
+        return thenApply(Schedulers.defaultScheduler(), fn);
     }
 
     /**
-     * Returns a new TaskResult that, when this task completes
+     * Returns a new Task that, when this task completes
+     * normally, is executed using the supplied Executor, with this
+     * task's result as the argument to the supplied function.
+     *
+     * @param executor the executor to use for asynchronous execution
+     * @param fn the function to use to compute the value of the returned Task
+     * @param <U> the function's return type
+     * @return the new Task
+     */
+    public <U, E extends Exception> Task<U> thenApply(Executor executor, ExceptionalFunction<T, U, E> fn) {
+        return thenApply(getCaller(), executor, fn);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, is executed using the supplied Executor, with this
+     * task's result as the argument to the supplied function.
+     *
+     * @param name the name of this new Task for displaying
+     * @param executor the executor to use for asynchronous execution
+     * @param fn the function to use to compute the value of the returned Task
+     * @param <U> the function's return type
+     * @return the new Task
+     */
+    public <U, E extends Exception> Task<U> thenApply(String name, Executor executor, ExceptionalFunction<T, U, E> fn) {
+        return new UniApply<>(fn).setExecutor(executor).setName(name);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, is executed using the default Executor, with this
+     * task's result as the argument to the supplied action.
+     *
+     * @param action the action to perform before completing the
+     * returned Task
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> thenAccept(ExceptionalConsumer<T, E> action) {
+        return thenAccept(Schedulers.defaultScheduler(), action);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, is executed using the supplied Executor, with this
+     * task's result as the argument to the supplied action.
+     *
+     * @param action the action to perform before completing the returned Task
+     * @param executor the executor to use for asynchronous execution
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> thenAccept(Executor executor, ExceptionalConsumer<T, E> action) {
+        return thenAccept(getCaller(), executor, action);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, is executed using the supplied Executor, with this
+     * task's result as the argument to the supplied action.
+     *
+     * @param name the name of this new Task for displaying
+     * @param action the action to perform before completing the returned Task
+     * @param executor the executor to use for asynchronous execution
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> thenAccept(String name, Executor executor, ExceptionalConsumer<T, E> action) {
+        return thenApply(name, executor, result -> {
+            action.accept(result);
+            return null;
+        });
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, executes the given action using the default Executor.
+     *
+     * @param action the action to perform before completing the
+     * returned Task
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> thenRun(ExceptionalRunnable<E> action) {
+        return thenRun(Schedulers.defaultScheduler(), action);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, executes the given action using the supplied Executor.
+     *
+     * @param action the action to perform before completing the
+     * returned Task
+     * @param executor the executor to use for asynchronous execution
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> thenRun(Executor executor, ExceptionalRunnable<E> action) {
+        return thenRun(getCaller(), executor, action);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, executes the given action using the supplied Executor.
+     *
+     * @param name the name of this new Task for displaying
+     * @param action the action to perform before completing the
+     * returned Task
+     * @param executor the executor to use for asynchronous execution
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> thenRun(String name, Executor executor, ExceptionalRunnable<E> action) {
+        return thenApply(name, executor, ignore -> {
+            action.run();
+            return null;
+        });
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, is executed using the default Executor.
+     *
+     * @param fn the function to use to compute the value of the returned Task
+     * @param <U> the function's return type
+     * @return the new Task
+     */
+    public final <U> Task<U> thenSupply(Callable<U> fn) {
+        return thenCompose(() -> Task.supplyAsync(fn));
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, is executed using the default Executor.
+     *
+     * @param name the name of this new Task for displaying
+     * @param fn the function to use to compute the value of the returned Task
+     * @param <U> the function's return type
+     * @return the new Task
+     */
+    public final <U> Task<U> thenSupply(String name, Callable<U> fn) {
+        return thenCompose(() -> Task.supplyAsync(name, fn));
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
      * normally, is executed.
      *
-     * @param fn the function returning a new TaskResult
-     * @param <U> the type of the returned TaskResult's result
-     * @return the TaskResult
+     * @param other the another Task
+     * @param <U> the type of the returned Task's result
+     * @return the Task
      */
-    public final <U> TaskResult<U> thenCompose(ExceptionalSupplier<TaskResult<U>, ?> fn) {
-        return new TaskResult<U>() {
-            TaskResult<U> then;
-
-            @Override
-            public Collection<? extends Task> getDependents() {
-                return Collections.singleton(Task.this);
-            }
-
-            @Override
-            public void execute() throws Exception {
-                then = fn.get().storeTo(this::setResult);
-            }
-
-            @Override
-            public Collection<? extends Task> getDependencies() {
-                return then == null ? Collections.emptyList() : Collections.singleton(then);
-            }
-        };
+    public final <U> Task<U> thenCompose(Task<U> other) {
+        return thenCompose(() -> other);
+    }
+    
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, is executed.
+     *
+     * @param fn the function returning a new Task
+     * @param <U> the type of the returned Task's result
+     * @return the Task
+     */
+    public final <U> Task<U> thenCompose(ExceptionalSupplier<Task<U>, ?> fn) {
+        return new UniCompose<>(fn, true);
     }
 
-    public final Task with(Task b) {
-        return with(convert(b));
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, is executed with result of this task as the argument
+     * to the supplied function.
+     *
+     * @param fn the function returning a new Task
+     * @param <U> the type of the returned Task's result
+     * @return the Task
+     */
+    public <U, E extends Exception> Task<U> thenCompose(ExceptionalFunction<T, Task<U>, E> fn) {
+        return new UniCompose<>(fn, true);
     }
 
-    public final <E extends Exception> Task with(ExceptionalSupplier<Task, E> b) {
-        return new CoupleTask(this, b, false);
+    public final <U> Task<U> withCompose(Task<U> other) {
+        return withCompose(() -> other);
+    }
+
+    public final <U, E extends Exception> Task<U> withCompose(ExceptionalSupplier<Task<U>, E> fn) {
+        return new UniCompose<>(fn, false);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, executes the given action using the default Executor.
+     *
+     * @param action the action to perform before completing the
+     * returned Task
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> withRun(ExceptionalRunnable<E> action) {
+        return withRun(Schedulers.defaultScheduler(), action);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, executes the given action using the supplied Executor.
+     *
+     * @param action the action to perform before completing the
+     * returned Task
+     * @param executor the executor to use for asynchronous execution
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> withRun(Executor executor, ExceptionalRunnable<E> action) {
+        return withRun(getCaller(), executor, action);
+    }
+
+    /**
+     * Returns a new Task that, when this task completes
+     * normally, executes the given action using the supplied Executor.
+     *
+     * @param name the name of this new Task for displaying
+     * @param action the action to perform before completing the
+     * returned Task
+     * @param executor the executor to use for asynchronous execution
+     * @return the new Task
+     */
+    public <E extends Exception> Task<Void> withRun(String name, Executor executor, ExceptionalRunnable<E> action) {
+        return new UniCompose<>(() -> Task.runAsync(name, executor, action), false);
     }
 
     /**
@@ -344,7 +583,7 @@ public abstract class Task {
      * @param action the action to perform
      * @return the new Task
      */
-    public final Task whenComplete(FinalizedCallback action) {
+    public final Task<Void> whenComplete(FinalizedCallback action) {
         return whenComplete(Schedulers.defaultScheduler(), action);
     }
 
@@ -361,35 +600,33 @@ public abstract class Task {
      * with this exception unless this task also completed exceptionally.
      *
      * @param action the action to perform
-     * @param scheduler the executor to use for asynchronous execution
+     * @param executor the executor to use for asynchronous execution
      * @return the new Task
      */
-    public final Task whenComplete(Scheduler scheduler, FinalizedCallback action) {
-        return new Task() {
+    public final Task<Void> whenComplete(Executor executor, FinalizedCallback action) {
+        return new Task<Void>() {
             {
                 setSignificance(TaskSignificance.MODERATE);
             }
 
-            @Override
-            public Scheduler getScheduler() {
-                return scheduler;
-            }
-
             @Override
             public void execute() throws Exception {
-                action.execute(isDependentsSucceeded(), Task.this.getLastException());
+                if (isDependentsSucceeded() != (Task.this.getException() == null))
+                    throw new AssertionError("When dependents succeeded, Task.exception must be nonnull.");
+
+                action.execute(Task.this.getException());
 
                 if (!isDependentsSucceeded()) {
                     setSignificance(TaskSignificance.MINOR);
-                    if (Task.this.getLastException() == null)
+                    if (Task.this.getException() == null)
                         throw new CancellationException();
                     else
-                        throw Task.this.getLastException();
+                        throw Task.this.getException();
                 }
             }
 
             @Override
-            public Collection<Task> getDependents() {
+            public Collection<Task<?>> getDependents() {
                 return Collections.singleton(Task.this);
             }
 
@@ -397,7 +634,26 @@ public abstract class Task {
             public boolean isRelyingOnDependents() {
                 return false;
             }
-        }.setName(getCaller());
+        }.setExecutor(executor).setName(getCaller());
+    }
+
+    /**
+     * Returns a new Task with the same exception as this task, that executes
+     * the given action when this task completes.
+     *
+     * <p>When this task is complete, the given action is invoked with the
+     * result (or {@code null} if none), a boolean value represents the
+     * execution status of this task, and the exception (or {@code null}
+     * if none) of this task as arguments.  The returned task is completed
+     * when the action returns.  If the supplied action itself encounters an
+     * exception, then the returned task exceptionally completes with this
+     * exception unless this task also completed exceptionally.
+     *
+     * @param action the action to perform
+     * @return the new Task
+     */
+    public Task<Void> whenComplete(Executor executor, FinalizedCallbackWithResult<T> action) {
+        return whenComplete(executor, (exception -> action.execute(getResult(), exception)));
     }
 
     /**
@@ -415,9 +671,9 @@ public abstract class Task {
      * @param failure the action to perform when this task exceptionally returned
      * @return the new Task
      */
-    public final <E1 extends Exception, E2 extends Exception> Task whenComplete(Scheduler scheduler, ExceptionalRunnable<E1> success, ExceptionalConsumer<Exception, E2> failure) {
-        return whenComplete(scheduler, (isDependentSucceeded, exception) -> {
-            if (isDependentSucceeded) {
+    public final <E1 extends Exception, E2 extends Exception> Task<Void> whenComplete(Executor executor, ExceptionalRunnable<E1> success, ExceptionalConsumer<Exception, E2> failure) {
+        return whenComplete(executor, exception -> {
+            if (exception == null) {
                 if (success != null)
                     try {
                         success.run();
@@ -433,44 +689,114 @@ public abstract class Task {
         });
     }
 
-    public static Task of(ExceptionalRunnable<?> closure) {
-        return of(Schedulers.defaultScheduler(), closure);
+    /**
+     * Returns a new Task with the same exception as this task, that executes
+     * the given actions when this task completes.
+     *
+     * <p>When this task is complete, the given success action is invoked with
+     * the result, the given failure action is invoked with the exception of
+     * this task.  The returned task is completed when the action returns.  If
+     * the supplied action itself encounters an exception, then the returned
+     * task exceptionally completes with this exception unless this task also
+     * completed exceptionally.
+     *
+     * @param success the action to perform when this task successfully completed
+     * @param failure the action to perform when this task exceptionally returned
+     * @return the new Task
+     */
+    public <E1 extends Exception, E2 extends Exception> Task<Void> whenComplete(Executor executor, ExceptionalConsumer<T, E1> success, ExceptionalConsumer<Exception, E2> failure) {
+        return whenComplete(executor, () -> success.accept(getResult()), failure);
     }
 
-    public static Task of(String name, ExceptionalRunnable<?> closure) {
-        return of(name, Schedulers.defaultScheduler(), closure);
+    public static Task<Void> runAsync(ExceptionalRunnable<?> closure) {
+        return runAsync(Schedulers.defaultScheduler(), closure);
     }
 
-    public static Task of(Scheduler scheduler, ExceptionalRunnable<?> closure) {
-        return of(getCaller(), scheduler, closure);
+    public static Task<Void> runAsync(String name, ExceptionalRunnable<?> closure) {
+        return runAsync(name, Schedulers.defaultScheduler(), closure);
     }
 
-    public static Task of(String name, Scheduler scheduler, ExceptionalRunnable<?> closure) {
-        return new SimpleTask(name, closure, scheduler);
+    public static Task<Void> runAsync(Executor executor, ExceptionalRunnable<?> closure) {
+        return runAsync(getCaller(), executor, closure);
     }
 
-    public static Task ofThen(ExceptionalSupplier<Task, ?> b) {
-        return new CoupleTask(null, b, true);
+    public static Task<Void> runAsync(String name, Executor executor, ExceptionalRunnable<?> closure) {
+        return new SimpleTask<>(closure.toCallable()).setExecutor(executor).setName(name);
     }
 
-    public static <V> TaskResult<V> ofResult(Callable<V> callable) {
-        return ofResult(getCaller(), callable);
-    }
+    public static <T> Task<T> composeAsync(ExceptionalSupplier<Task<T>, ?> fn) {
+        return new Task<T>() {
+            Task<T> then;
 
-    public static <V> TaskResult<V> ofResult(String name, Callable<V> callable) {
-        return new SimpleTaskResult<>(callable).setName(name);
-    }
-
-    private static ExceptionalSupplier<Task, ?> convert(Task t) {
-        return new ExceptionalSupplier<Task, Exception>() {
             @Override
-            public Task get() {
-                return t;
+            public void execute() throws Exception {
+                then = fn.get();
+                if (then != null)
+                    then.storeTo(this::setResult);
             }
 
             @Override
-            public String toString() {
-                return t.getName();
+            public Collection<Task<?>> getDependencies() {
+                return then == null ? Collections.emptySet() : Collections.singleton(then);
+            }
+        };
+    }
+
+    public static <V> Task<V> supplyAsync(Callable<V> callable) {
+        return supplyAsync(getCaller(), callable);
+    }
+
+    public static <V> Task<V> supplyAsync(Executor executor, Callable<V> callable) {
+        return supplyAsync(getCaller(), executor, callable);
+    }
+
+    public static <V> Task<V> supplyAsync(String name, Callable<V> callable) {
+        return supplyAsync(name, Schedulers.defaultScheduler(), callable);
+    }
+
+    public static <V> Task<V> supplyAsync(String name, Executor executor, Callable<V> callable) {
+        return new SimpleTask<>(callable).setExecutor(executor).setName(name);
+    }
+
+    /**
+     * Returns a new Task that is completed when all of the given Tasks
+     * complete.  If any of the given Tasks complete exceptionally,
+     * then the returned Task also does so.  Otherwise, the results, if
+     * any, of the given Tasks are not reflected in the returned Task,
+     * but may be obtained by inspecting them individually. If no Tasks
+     * are provided, returns a Task completed with the value {@code null}.
+     *
+     * @param tasks the Tasks
+     * @return a new Task that is completed when all of the given Tasks complete
+     */
+    public static Task<Void> allOf(Task<?>... tasks) {
+        return allOf(Arrays.asList(tasks));
+    }
+
+    /**
+     * Returns a new Task that is completed when all of the given Tasks
+     * complete.  If any of the given Tasks complete exceptionally,
+     * then the returned Task also does so.  Otherwise, the results, if
+     * any, of the given Tasks are not reflected in the returned Task,
+     * but may be obtained by inspecting them individually. If no Tasks
+     * are provided, returns a Task completed with the value {@code null}.
+     *
+     * @param tasks the Tasks
+     * @return a new Task that is completed when all of the given Tasks complete
+     */
+    public static Task<Void> allOf(Collection<Task<?>> tasks) {
+        return new Task<Void>() {
+            {
+                setSignificance(TaskSignificance.MINOR);
+            }
+
+            @Override
+            public void execute() {
+            }
+
+            @Override
+            public Collection<Task<?>> getDependents() {
+                return tasks;
             }
         };
     }
@@ -498,10 +824,105 @@ public abstract class Task {
     }
 
     public interface FinalizedCallback {
-        void execute(boolean isDependentSucceeded, Exception exception) throws Exception;
+        void execute(Exception exception) throws Exception;
     }
 
-    static String getCaller() {
+    public interface FinalizedCallbackWithResult<T> {
+        void execute(T result, Exception exception) throws Exception;
+    }
+
+    private static String getCaller() {
         return ReflectionHelper.getCaller(packageName -> !"org.jackhuang.hmcl.task".equals(packageName)).toString();
     }
+
+    private static final class SimpleTask<T> extends Task<T> {
+
+        private final Callable<T> callable;
+
+        SimpleTask(Callable<T> callable) {
+            this.callable = callable;
+        }
+
+        @Override
+        public void execute() throws Exception {
+            setResult(callable.call());
+        }
+    }
+
+    private class UniApply<R> extends Task<R> {
+        private final ExceptionalFunction<T, R, ?> callable;
+
+        UniApply(ExceptionalFunction<T, R, ?> callable) {
+            this.callable = callable;
+        }
+
+        @Override
+        public Collection<Task<?>> getDependents() {
+            return Collections.singleton(Task.this);
+        }
+
+        @Override
+        public void execute() throws Exception {
+            setResult(callable.apply(Task.this.getResult()));
+        }
+    }
+
+    /**
+     * A task that combines two tasks and make sure [pred] runs before succ.
+     *
+     * @author huangyuhui
+     */
+    private final class UniCompose<U> extends Task<U> {
+
+        private final boolean relyingOnDependents;
+        private Task<U> succ;
+        private final ExceptionalFunction<T, Task<U>, ?> fn;
+
+        /**
+         * A task that combines two tasks and make sure pred runs before succ.
+         *
+         * @param fn a callback that returns the task runs after pred, succ will be executed asynchronously. You can do something that relies on the result of pred.
+         * @param relyingOnDependents true if this task chain will be broken when task pred fails.
+         */
+        UniCompose(ExceptionalSupplier<Task<U>, ?> fn, boolean relyingOnDependents) {
+            this(result -> fn.get(), relyingOnDependents);
+        }
+
+        /**
+         * A task that combines two tasks and make sure pred runs before succ.
+         *
+         * @param fn a callback that returns the task runs after pred, succ will be executed asynchronously. You can do something that relies on the result of pred.
+         * @param relyingOnDependents true if this task chain will be broken when task pred fails.
+         */
+        UniCompose(ExceptionalFunction<T, Task<U>, ?> fn, boolean relyingOnDependents) {
+            this.fn = fn;
+            this.relyingOnDependents = relyingOnDependents;
+
+            setSignificance(TaskSignificance.MODERATE);
+            setName(fn.toString());
+        }
+
+        @Override
+        public void execute() throws Exception {
+            setName(fn.toString());
+            succ = fn.apply(Task.this.getResult());
+            if (succ != null)
+                succ.storeTo(this::setResult);
+        }
+
+        @Override
+        public Collection<Task<?>> getDependents() {
+            return Collections.singleton(Task.this);
+        }
+
+        @Override
+        public Collection<Task<?>> getDependencies() {
+            return succ == null ? Collections.emptySet() : Collections.singleton(succ);
+        }
+
+        @Override
+        public boolean isRelyingOnDependents() {
+            return relyingOnDependents;
+        }
+    }
 }

HMCLCore/src/main/java/org/jackhuang/hmcl/task/TaskEvent.java

@@ -25,16 +25,16 @@ import org.jackhuang.hmcl.event.Event;
  */
 public class TaskEvent extends Event {
 
-    private final Task task;
+    private final Task<?> task;
     private final boolean failed;
 
-    public TaskEvent(Object source, Task task, boolean failed) {
+    public TaskEvent(Object source, Task<?> task, boolean failed) {
         super(source);
         this.task = task;
         this.failed = failed;
     }
 
-    public Task getTask() {
+    public Task<?> getTask() {
         return task;
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/task/TaskExecutor.java

@@ -17,12 +17,15 @@
  */
 package org.jackhuang.hmcl.task;
 
-import org.jackhuang.hmcl.util.*;
+import org.jackhuang.hmcl.util.Lang;
+import org.jackhuang.hmcl.util.Logging;
 import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
 
-import java.util.*;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.concurrent.*;
-import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Level;
 
@@ -32,15 +35,13 @@ import java.util.logging.Level;
  */
 public final class TaskExecutor {
 
-    private final Task firstTask;
+    private final Task<?> firstTask;
     private final List<TaskListener> taskListeners = new LinkedList<>();
-    private boolean canceled = false;
-    private Exception lastException;
+    private Exception exception;
     private final AtomicInteger totTask = new AtomicInteger(0);
-    private final ConcurrentLinkedQueue<Future<?>> workerQueue = new ConcurrentLinkedQueue<>();
-    private Scheduler scheduler = Schedulers.newThread();
+    private CompletableFuture<Boolean> future;
 
-    public TaskExecutor(Task task) {
+    public TaskExecutor(Task<?> task) {
         this.firstTask = task;
     }
 
@@ -48,222 +49,208 @@ public final class TaskExecutor {
         taskListeners.add(taskListener);
     }
 
-    public boolean isCanceled() {
-        return canceled;
-    }
-
-    public Exception getLastException() {
-        return lastException;
-    }
-
-    public void setScheduler(Scheduler scheduler) {
-        this.scheduler = Objects.requireNonNull(scheduler);
+    public Exception getException() {
+        return exception;
     }
 
     public TaskExecutor start() {
         taskListeners.forEach(TaskListener::onStart);
-        workerQueue.add(scheduler.schedule(() -> {
-            boolean flag = executeTasks(Collections.singleton(firstTask));
-            taskListeners.forEach(it -> it.onStop(flag, this));
-        }));
+        future = executeTasks(Collections.singleton(firstTask))
+                .thenApplyAsync(exception -> {
+                    boolean success = exception == null;
+
+                    if (!success) {
+                        // We log exception stacktrace because some of exceptions occurred because of bugs.
+                        Logging.LOG.log(Level.WARNING, "An exception occurred in task execution", exception);
+                    }
+
+                    taskListeners.forEach(it -> it.onStop(success, this));
+                    return success;
+                })
+                .exceptionally(e -> {
+                    Lang.handleUncaughtException(resolveException(e));
+                    return false;
+                });
         return this;
     }
 
     public boolean test() {
-        taskListeners.forEach(TaskListener::onStart);
-        AtomicBoolean flag = new AtomicBoolean(true);
-        Future<?> future = scheduler.schedule(() -> {
-            flag.set(executeTasks(Collections.singleton(firstTask)));
-            taskListeners.forEach(it -> it.onStop(flag.get(), this));
-        });
-        workerQueue.add(future);
+        start();
         try {
-            future.get();
+            return future.get();
         } catch (InterruptedException e) {
             Thread.currentThread().interrupt();
-        } catch (ExecutionException | CancellationException e) {
+        } catch (ExecutionException ignore) {
+            // We have dealt with ExecutionException in exception handling and uncaught exception handler.
+        } catch (CancellationException e) {
+            Logging.LOG.log(Level.INFO, "Task " + firstTask + " has been cancelled.", e);
         }
-        return flag.get();
+        return false;
     }
 
     /**
      * Cancel the subscription ant interrupt all tasks.
      */
     public synchronized void cancel() {
-        canceled = true;
-
-        while (!workerQueue.isEmpty()) {
-            Future<?> future = workerQueue.poll();
-            if (future != null)
-                future.cancel(true);
+        if (future == null) {
+            throw new IllegalStateException("Cannot cancel a not started TaskExecutor");
         }
+
+        future.cancel(true);
     }
 
-    private boolean executeTasks(Collection<? extends Task> tasks) throws InterruptedException {
-        if (tasks.isEmpty())
-            return true;
+    private CompletableFuture<Exception> executeTasks(Collection<Task<?>> tasks) {
+        if (tasks == null || tasks.isEmpty())
+            return CompletableFuture.completedFuture(null);
 
-        totTask.addAndGet(tasks.size());
-        AtomicBoolean success = new AtomicBoolean(true);
-        CountDownLatch latch = new CountDownLatch(tasks.size());
-        for (Task task : tasks) {
-            if (canceled)
-                return false;
-            Invoker invoker = new Invoker(task, latch, success);
-            try {
-                Future<?> future = scheduler.schedule(invoker);
-                if (future != null)
-                    workerQueue.add(future);
-            } catch (RejectedExecutionException e) {
-                throw new InterruptedException();
-            }
-        }
+        return CompletableFuture.completedFuture(null)
+                .thenComposeAsync(unused -> {
+                    totTask.addAndGet(tasks.size());
 
-        if (canceled)
-            return false;
-
-        try {
-            latch.await();
-        } catch (InterruptedException e) {
-            return false;
-        }
-        return success.get() && !canceled;
+                    return CompletableFuture.allOf(tasks.stream()
+                            .map(task -> CompletableFuture.completedFuture(null)
+                                    .thenComposeAsync(unused2 -> executeTask(task))
+                            ).toArray(CompletableFuture<?>[]::new));
+                })
+                .thenApplyAsync(unused -> (Exception) null)
+                .exceptionally(throwable -> {
+                    Throwable resolved = resolveException(throwable);
+                    if (resolved instanceof Exception) {
+                        return (Exception) resolved;
+                    } else {
+                        // If an error occurred, we just rethrow it.
+                        throw new CompletionException(throwable);
+                    }
+                });
     }
 
-    private boolean executeTask(Task task) {
-        if (canceled) {
-            task.setState(Task.TaskState.FAILED);
-            task.setLastException(new CancellationException());
-            return false;
-        }
+    private CompletableFuture<?> executeTask(Task<?> task) {
+        return CompletableFuture.completedFuture(null)
+                .thenComposeAsync(unused -> {
+                    task.setState(Task.TaskState.READY);
 
-        task.setState(Task.TaskState.READY);
+                    if (task.getSignificance().shouldLog())
+                        Logging.LOG.log(Level.FINE, "Executing task: " + task.getName());
 
-        if (task.getSignificance().shouldLog())
-            Logging.LOG.log(Level.FINE, "Executing task: " + task.getName());
+                    taskListeners.forEach(it -> it.onReady(task));
 
-        taskListeners.forEach(it -> it.onReady(task));
+                    if (task.doPreExecute()) {
+                        return CompletableFuture.runAsync(wrap(task::preExecute), task.getExecutor());
+                    } else {
+                        return CompletableFuture.completedFuture(null);
+                    }
+                })
+                .thenComposeAsync(unused -> executeTasks(task.getDependents()))
+                .thenComposeAsync(dependentsException -> {
+                    boolean isDependentsSucceeded = dependentsException == null;
 
-        boolean flag = false;
+                    if (!isDependentsSucceeded && task.isRelyingOnDependents()) {
+                        task.setException(dependentsException);
+                        rethrow(dependentsException);
+                    }
 
-        try {
-            if (task.doPreExecute()) {
-                try {
-                    task.getScheduler().schedule(task::preExecute).get();
-                } catch (ExecutionException e) {
-                    if (e.getCause() instanceof Exception)
-                        throw (Exception) e.getCause();
-                    else
-                        throw e;
-                }
-            }
+                    if (isDependentsSucceeded)
+                        task.setDependentsSucceeded();
 
-            Collection<? extends Task> dependents = task.getDependents();
-            boolean doDependentsSucceeded = executeTasks(dependents);
-            Exception dependentsException = dependents.stream().map(Task::getLastException).filter(Objects::nonNull).findAny().orElse(null);
-            if (!doDependentsSucceeded && task.isRelyingOnDependents() || canceled) {
-                task.setLastException(dependentsException);
-                throw new CancellationException();
-            }
+                    return CompletableFuture.runAsync(wrap(() -> {
+                        task.setState(Task.TaskState.RUNNING);
+                        taskListeners.forEach(it -> it.onRunning(task));
+                        task.execute();
+                    }), task.getExecutor()).whenComplete((unused, throwable) -> {
+                        task.setState(Task.TaskState.EXECUTED);
+                        rethrow(throwable);
+                    });
+                })
+                .thenComposeAsync(unused -> executeTasks(task.getDependencies()))
+                .thenComposeAsync(dependenciesException -> {
+                    boolean isDependenciesSucceeded = dependenciesException == null;
 
-            if (doDependentsSucceeded)
-                task.setDependentsSucceeded();
+                    if (isDependenciesSucceeded)
+                        task.setDependenciesSucceeded();
 
-            try {
-                task.getScheduler().schedule(() -> {
-                    task.setState(Task.TaskState.RUNNING);
-                    taskListeners.forEach(it -> it.onRunning(task));
-                    task.execute();
-                }).get();
-            } catch (ExecutionException e) {
-                if (e.getCause() instanceof Exception)
-                    throw (Exception) e.getCause();
-                else
-                    throw e;
-            } finally {
-                task.setState(Task.TaskState.EXECUTED);
-            }
+                    if (task.doPostExecute()) {
+                        return CompletableFuture.runAsync(wrap(task::postExecute), task.getExecutor())
+                                .thenApply(unused -> dependenciesException);
+                    } else {
+                        return CompletableFuture.completedFuture(dependenciesException);
+                    }
+                })
+                .thenAcceptAsync(dependenciesException -> {
+                    boolean isDependenciesSucceeded = dependenciesException == null;
 
-            Collection<? extends Task> dependencies = task.getDependencies();
-            boolean doDependenciesSucceeded = executeTasks(dependencies);
-            Exception dependenciesException = dependencies.stream().map(Task::getLastException).filter(Objects::nonNull).findAny().orElse(null);
+                    if (!isDependenciesSucceeded && task.isRelyingOnDependencies()) {
+                        Logging.LOG.severe("Subtasks failed for " + task.getName());
+                        task.setException(dependenciesException);
+                        rethrow(dependenciesException);
+                    }
 
-            if (doDependenciesSucceeded)
-                task.setDependenciesSucceeded();
+                    if (task.getSignificance().shouldLog()) {
+                        Logging.LOG.log(Level.FINER, "Task finished: " + task.getName());
+                    }
 
-            if (task.doPostExecute()) {
-                try {
-                    task.getScheduler().schedule(task::postExecute).get();
-                } catch (ExecutionException e) {
-                    if (e.getCause() instanceof Exception)
-                        throw (Exception) e.getCause();
-                    else
-                        throw e;
-                }
-            }
+                    task.onDone().fireEvent(new TaskEvent(this, task, false));
+                    taskListeners.forEach(it -> it.onFinished(task));
 
-            if (!doDependenciesSucceeded && task.isRelyingOnDependencies()) {
-                Logging.LOG.severe("Subtasks failed for " + task.getName());
-                task.setLastException(dependenciesException);
-                throw new CancellationException();
-            }
+                    task.setState(Task.TaskState.SUCCEEDED);
+                })
+                .exceptionally(throwable -> {
+                    Throwable resolved = resolveException(throwable);
+                    if (resolved instanceof Exception) {
+                        Exception e = (Exception) resolved;
+                        if (e instanceof InterruptedException) {
+                            task.setException(e);
+                            if (task.getSignificance().shouldLog()) {
+                                Logging.LOG.log(Level.FINE, "Task aborted: " + task.getName());
+                            }
+                            task.onDone().fireEvent(new TaskEvent(this, task, true));
+                            taskListeners.forEach(it -> it.onFailed(task, e));
+                        } else {
+                            task.setException(e);
+                            exception = e;
+                            if (task.getSignificance().shouldLog()) {
+                                Logging.LOG.log(Level.FINE, "Task failed: " + task.getName(), e);
+                            }
+                            task.onDone().fireEvent(new TaskEvent(this, task, true));
+                            taskListeners.forEach(it -> it.onFailed(task, e));
+                        }
 
-            flag = true;
-            if (task.getSignificance().shouldLog()) {
-                Logging.LOG.log(Level.FINER, "Task finished: " + task.getName());
-            }
+                        task.setState(Task.TaskState.FAILED);
+                    }
 
-            task.onDone().fireEvent(new TaskEvent(this, task, false));
-            taskListeners.forEach(it -> it.onFinished(task));
-        } catch (InterruptedException e) {
-            task.setLastException(e);
-            if (task.getSignificance().shouldLog()) {
-                Logging.LOG.log(Level.FINE, "Task aborted: " + task.getName());
-            }
-            task.onDone().fireEvent(new TaskEvent(this, task, true));
-            taskListeners.forEach(it -> it.onFailed(task, e));
-        } catch (CancellationException | RejectedExecutionException e) {
-            if (task.getLastException() == null)
-                task.setLastException(e);
-        } catch (Exception e) {
-            task.setLastException(e);
-            lastException = e;
-            if (task.getSignificance().shouldLog()) {
-                Logging.LOG.log(Level.FINE, "Task failed: " + task.getName(), e);
-            }
-            task.onDone().fireEvent(new TaskEvent(this, task, true));
-            taskListeners.forEach(it -> it.onFailed(task, e));
-        }
-        task.setState(flag ? Task.TaskState.SUCCEEDED : Task.TaskState.FAILED);
-        return flag;
+                    throw new CompletionException(resolved); // rethrow error
+                });
     }
 
     public int getRunningTasks() {
         return totTask.get();
     }
 
-    private class Invoker implements ExceptionalRunnable<Exception> {
+    private static Throwable resolveException(Throwable e) {
+        if (e instanceof ExecutionException || e instanceof CompletionException)
+            return resolveException(e.getCause());
+        else
+            return e;
+    }
 
-        private final Task task;
-        private final CountDownLatch latch;
-        private final AtomicBoolean success;
-
-        public Invoker(Task task, CountDownLatch latch, AtomicBoolean success) {
-            this.task = task;
-            this.latch = latch;
-            this.success = success;
+    private static void rethrow(Throwable e) {
+        if (e == null)
+            return;
+        if (e instanceof ExecutionException || e instanceof CompletionException) { // including UncheckedException and UncheckedThrowable
+            rethrow(e.getCause());
+        } else if (e instanceof RuntimeException) {
+            throw (RuntimeException) e;
+        } else {
+            throw new CompletionException(e);
         }
+    }
 
-        @Override
-        public void run() {
+    private static Runnable wrap(ExceptionalRunnable<?> runnable) {
+        return () -> {
             try {
-                Thread.currentThread().setName(task.getName());
-                if (!executeTask(task))
-                    success.set(false);
-            } finally {
-                latch.countDown();
+                runnable.run();
+            } catch (Exception e) {
+                rethrow(e);
             }
-        }
-
+        };
     }
 }

HMCLCore/src/main/java/org/jackhuang/hmcl/task/TaskListener.java

@@ -25,29 +25,57 @@ import java.util.EventListener;
  */
 public abstract class TaskListener implements EventListener {
 
+    /**
+     * Executed when a Task execution chain starts.
+     */
     public void onStart() {
     }
 
-    public void onReady(Task task) {
+    /**
+     * Executed before the task's pre-execution and dependents execution.
+     *
+     * TaskState of this task is READY.
+     *
+     * @param task the task that gets ready.
+     */
+    public void onReady(Task<?> task) {
     }
 
-    public void onRunning(Task task) {
+    /**
+     * Executed when the task's execution starts.
+     *
+     * TaskState of this task is RUNNING.
+     *
+     * @param task the task which is being run.
+     */
+    public void onRunning(Task<?> task) {
     }
 
-    public void onFinished(Task task) {
+    /**
+     * Executed after the task's dependencies and post-execution finished.
+     *
+     * TaskState of the task is EXECUTED.
+     *
+     * @param task the task which finishes its work.
+     */
+    public void onFinished(Task<?> task) {
     }
 
-    public void onFailed(Task task, Throwable throwable) {
+    /**
+     * Executed when an exception occurred during the task's execution.
+     *
+     * @param task the task which finishes its work.
+     */
+    public void onFailed(Task<?> task, Throwable throwable) {
         onFinished(task);
     }
 
+    /**
+     * Executed when the task execution chain stopped.
+     *
+     * @param success true if no error occurred during task execution.
+     * @param executor the task executor with responsibility to the task execution.
+     */
     public void onStop(boolean success, TaskExecutor executor) {
     }
-
-    public static class DefaultTaskListener extends TaskListener {
-        private DefaultTaskListener() {
-        }
-
-        public static final DefaultTaskListener INSTANCE = new DefaultTaskListener();
-    }
 }

HMCLCore/src/main/java/org/jackhuang/hmcl/task/TaskResult.java

@@ -1,247 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.task;
-
-import org.jackhuang.hmcl.util.function.ExceptionalConsumer;
-import org.jackhuang.hmcl.util.function.ExceptionalFunction;
-
-import java.util.Collection;
-import java.util.Collections;
-import java.util.function.Consumer;
-
-/**
- * A task that has a result.
- *
- * @author huangyuhui
- */
-public abstract class TaskResult<T> extends Task {
-
-    private T result;
-    private Consumer<T> resultConsumer;
-
-    @Override
-    public TaskResult<T> setName(String name) {
-        super.setName(name);
-        return this;
-    }
-
-    /**
-     * Returns the result of this task.
-     *
-     * The result will be generated only if the execution is completed.
-     */
-    public T getResult() {
-        return result;
-    }
-
-    protected void setResult(T result) {
-        this.result = result;
-        if (resultConsumer != null)
-            resultConsumer.accept(result);
-    }
-
-    /**
-     * Sync the result of this task by given action.
-     *
-     * @param action the action to perform when result of this task changed
-     * @return this TaskResult
-     */
-    public TaskResult<T> storeTo(Consumer<T> action) {
-        this.resultConsumer = action;
-        return this;
-    }
-
-    /**
-     * Returns a new TaskResult that, when this task completes
-     * normally, is executed with result of this task as the argument
-     * to the supplied function.
-     *
-     * @param fn the function returning a new TaskResult
-     * @param <U> the type of the returned TaskResult's result
-     * @return the TaskResult
-     */
-    public <U, E extends Exception> TaskResult<U> thenCompose(ExceptionalFunction<T, TaskResult<U>, E> fn) {
-        return new TaskResult<U>() {
-            TaskResult<U> then;
-
-            @Override
-            public Collection<? extends Task> getDependents() {
-                return Collections.singleton(TaskResult.this);
-            }
-
-            @Override
-            public void execute() throws Exception {
-                then = fn.apply(TaskResult.this.getResult()).storeTo(this::setResult);
-            }
-
-            @Override
-            public Collection<? extends Task> getDependencies() {
-                return then == null ? Collections.emptyList() : Collections.singleton(then);
-            }
-        };
-    }
-
-    /**
-     * Returns a new Task that, when this task completes
-     * normally, is executed with this task as the argument
-     * to the supplied function.
-     *
-     * @param fn the function returning a new Task
-     * @return the Task
-     */
-    public <E extends Exception> Task then(ExceptionalFunction<T, Task, E> fn) {
-        return new CoupleTask(this, () -> fn.apply(getResult()), true);
-    }
-
-    /**
-     * Returns a new TaskResult that, when this task completes
-     * normally, is executed using the default Scheduler, with this
-     * task's result as the argument to the supplied function.
-     *
-     * @param fn the function to use to compute the value of the returned TaskResult
-     * @param <U> the function's return type
-     * @return the new TaskResult
-     */
-    public <U, E extends Exception> TaskResult<U> thenApply(ExceptionalFunction<T, U, E> fn) {
-        return thenApply(Schedulers.defaultScheduler(), fn);
-    }
-
-    /**
-     * Returns a new TaskResult that, when this task completes
-     * normally, is executed using the supplied Scheduler, with this
-     * task's result as the argument to the supplied function.
-     *
-     * @param scheduler the executor to use for asynchronous execution
-     * @param fn the function to use to compute the value of the returned TaskResult
-     * @param <U> the function's return type
-     * @return the new TaskResult
-     */
-    public <U, E extends Exception> TaskResult<U> thenApply(Scheduler scheduler, ExceptionalFunction<T, U, E> fn) {
-        return thenApply(getCaller(), scheduler, fn);
-    }
-
-    /**
-     * Returns a new TaskResult that, when this task completes
-     * normally, is executed using the supplied Scheduler, with this
-     * task's result as the argument to the supplied function.
-     *
-     * @param name the name of this new TaskResult for displaying
-     * @param scheduler the executor to use for asynchronous execution
-     * @param fn the function to use to compute the value of the returned TaskResult
-     * @param <U> the function's return type
-     * @return the new TaskResult
-     */
-    public <U, E extends Exception> TaskResult<U> thenApply(String name, Scheduler scheduler, ExceptionalFunction<T, U, E> fn) {
-        return new Subtask<>(name, scheduler, fn);
-    }
-
-    /**
-     * Returns a new Task that, when this task completes
-     * normally, is executed using the default Scheduler, with this
-     * task's result as the argument to the supplied action.
-     *
-     * @param action the action to perform before completing the
-     * returned Task
-     * @return the new Task
-     */
-    public <E extends Exception> Task thenAccept(ExceptionalConsumer<T, E> action) {
-        return thenAccept(Schedulers.defaultScheduler(), action);
-    }
-
-    /**
-     * Returns a new Task that, when this task completes
-     * normally, is executed using the supplied Scheduler, with this
-     * task's result as the argument to the supplied action.
-     *
-     * @param action the action to perform before completing the returned Task
-     * @param scheduler the executor to use for asynchronous execution
-     * @return the new Task
-     */
-    public <E extends Exception> Task thenAccept(Scheduler scheduler, ExceptionalConsumer<T, E> action) {
-        return new CoupleTask(this, () -> Task.of(scheduler, () -> action.accept(getResult())), true);
-    }
-
-    /**
-     * Returns a new Task with the same exception as this task, that executes
-     * the given actions when this task completes.
-     *
-     * <p>When this task is complete, the given success action is invoked with
-     * the result, the given failure action is invoked with the exception of
-     * this task.  The returned task is completed when the action returns.  If
-     * the supplied action itself encounters an exception, then the returned
-     * task exceptionally completes with this exception unless this task also
-     * completed exceptionally.
-     *
-     * @param success the action to perform when this task successfully completed
-     * @param failure the action to perform when this task exceptionally returned
-     * @return the new Task
-     */
-    public <E1 extends Exception, E2 extends Exception> Task whenComplete(Scheduler scheduler, ExceptionalConsumer<T, E1> success, ExceptionalConsumer<Exception, E2> failure) {
-        return whenComplete(scheduler, () -> success.accept(getResult()), failure);
-    }
-
-    /**
-     * Returns a new Task with the same exception as this task, that executes
-     * the given action when this task completes.
-     *
-     * <p>When this task is complete, the given action is invoked with the
-     * result (or {@code null} if none), a boolean value represents the
-     * execution status of this task, and the exception (or {@code null}
-     * if none) of this task as arguments.  The returned task is completed
-     * when the action returns.  If the supplied action itself encounters an
-     * exception, then the returned task exceptionally completes with this
-     * exception unless this task also completed exceptionally.
-     *
-     * @param action the action to perform
-     * @return the new Task
-     */
-    public Task whenComplete(Scheduler scheduler, FinalizedCallback<T> action) {
-        return whenComplete(scheduler, ((isDependentSucceeded, exception) -> action.execute(getResult(), isDependentSucceeded, exception)));
-    }
-
-    private class Subtask<R> extends TaskResult<R> {
-        private final Scheduler scheduler;
-        private final ExceptionalFunction<T, R, ?> callable;
-
-        public Subtask(String name, Scheduler scheduler, ExceptionalFunction<T, R, ?> callable) {
-            this.scheduler = scheduler;
-            this.callable = callable;
-
-            setName(name);
-        }
-
-        @Override
-        public Collection<? extends Task> getDependents() {
-            return Collections.singleton(TaskResult.this);
-        }
-
-        @Override
-        public Scheduler getScheduler() {
-            return scheduler;
-        }
-
-        @Override
-        public void execute() throws Exception {
-            setResult(callable.apply(TaskResult.this.getResult()));
-        }
-    }
-
-    public interface FinalizedCallback<V> {
-        void execute(V result, boolean isDependentSucceeded, Exception exception) throws Exception;
-    }
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/util/AutoTypingMap.java

@@ -1,77 +0,0 @@
-/*
- * Hello Minecraft! Launcher
- * Copyright (C) 2019  huangyuhui <huanghongxun2008@126.com> and contributors
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-package org.jackhuang.hmcl.util;
-
-import java.util.Collection;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Set;
-
-/**
- * A map that support auto casting.
- *
- * @author huangyuhui
- */
-public final class AutoTypingMap<K> {
-
-    private final Map<K, Object> impl;
-
-    public AutoTypingMap(Map<K, Object> impl) {
-        this.impl = impl;
-    }
-
-    /**
-     * Get the value associated with given {@code key} in the mapping.
-     *
-     * Be careful of the return type {@code <V>}, as you must ensure that {@code <V>} is correct
-     *
-     * @param key the key that the value associated with
-     * @param <V> the type of value which you must ensure type correction
-     * @return the value associated with given {@code key}
-     * @throws ClassCastException if the return type {@code <V>} is incorrect.
-     */
-    @SuppressWarnings("unchecked")
-    public synchronized <V> V get(K key) throws ClassCastException {
-        return (V) impl.get(key);
-    }
-
-    public synchronized  <V> Optional<V> getOptional(K key) {
-        return Optional.ofNullable(get(key));
-    }
-
-    public synchronized void set(K key, Object value) {
-        if (value != null)
-            impl.put(key, value);
-    }
-
-    public Collection<Object> values() {
-        return impl.values();
-    }
-
-    public Set<K> keys() {
-        return impl.keySet();
-    }
-
-    public boolean containsKey(K key) {
-        return impl.containsKey(key);
-    }
-
-    public Object remove(K key) {
-        return impl.remove(key);
-    }
-}

HMCLCore/src/main/java/org/jackhuang/hmcl/util/function/ExceptionalRunnable.java

@@ -27,15 +27,11 @@ public interface ExceptionalRunnable<E extends Exception> {
 
     void run() throws E;
 
-    default Callable<?> toCallable() {
+    default Callable<Void> toCallable() {
         return () -> {
             run();
             return null;
         };
     }
 
-    static ExceptionalRunnable<?> fromRunnable(Runnable r) {
-        return r::run;
-    }
-
 }

HMCLCore/src/main/java/org/jackhuang/hmcl/util/io/NetworkUtils.java

@@ -19,7 +19,6 @@ package org.jackhuang.hmcl.util.io;
 
 import java.io.*;
 import java.net.*;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;

HMCLCore/src/test/java/org/jackhuang/hmcl/util/TaskTest.java

@@ -0,0 +1,107 @@
+package org.jackhuang.hmcl.util;
+
+import javafx.embed.swing.JFXPanel;
+import org.jackhuang.hmcl.task.Schedulers;
+import org.jackhuang.hmcl.task.Task;
+import org.jackhuang.hmcl.task.TaskExecutor;
+import org.jackhuang.hmcl.util.platform.JavaVersion;
+import org.junit.Assert;
+import org.junit.Assume;
+import org.junit.Test;
+
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+
+public class TaskTest {
+    /**
+     * TaskExecutor will not catch error and will be thrown to global handler.
+     */
+    @Test
+    public void expectErrorUncaught() {
+        AtomicReference<Throwable> throwable = new AtomicReference<>();
+        Thread.setDefaultUncaughtExceptionHandler((t, e) -> throwable.set(e));
+        Assert.assertFalse(Task.composeAsync(() -> Task.allOf(
+                Task.allOf(Task.runAsync(() -> {
+                    throw new Error();
+                }))
+        )).whenComplete(Assert::assertNull).test());
+
+        Assert.assertTrue("Error has not been thrown to uncaught exception handler", throwable.get() instanceof Error);
+    }
+
+    /**
+     *
+     */
+    @Test
+    public void testWhenComplete() {
+        boolean result = Task.supplyAsync(() -> {
+            throw new IllegalStateException();
+        }).whenComplete(exception -> {
+            Assert.assertTrue(exception instanceof IllegalStateException);
+        }).test();
+
+        Assert.assertFalse("Task should fail at this case", result);
+    }
+
+    @Test
+    public void testWithCompose() {
+        AtomicBoolean bool = new AtomicBoolean();
+        boolean success = Task.supplyAsync(() -> {
+            throw new IllegalStateException();
+        }).withRun(() -> {
+            bool.set(true);
+        }).test();
+
+        Assert.assertTrue("Task should success because withRun will ignore previous exception", success);
+        Assert.assertTrue("withRun should be executed", bool.get());
+    }
+
+    @Test
+    public void testThenAccept() {
+        new JFXPanel(); // init JavaFX Toolkit
+        AtomicBoolean flag = new AtomicBoolean();
+        boolean result = Task.supplyAsync(JavaVersion::fromCurrentEnvironment)
+                .thenAccept(Schedulers.javafx(), javaVersion -> {
+                    flag.set(true);
+                    Assert.assertEquals(javaVersion, JavaVersion.fromCurrentEnvironment());
+                })
+                .test();
+
+        Assert.assertTrue("Task does not succeed", result);
+        Assert.assertTrue("ThenAccept has not been executed", flag.get());
+    }
+
+    @Test
+    public void testCancellation() {
+        Task<?> task = Task.runAsync(() -> Thread.sleep(200));
+        TaskExecutor executor = task.executor();
+        Lang.thread(() -> {
+            try {
+                Thread.sleep(100);
+                executor.cancel();
+            } catch (InterruptedException e) {
+                Assume.assumeNoException(e);
+            }
+        });
+        Assert.assertFalse("Task should fail because we have cancelled it", executor.test());
+        Assert.assertNull("CancellationException should not be recorded.", executor.getException());
+        Assert.assertNull("CancellationException should not be recorded.", task.getException());
+    }
+
+    @Test
+    public void testRejectedExecutionException() {
+        Schedulers.defaultScheduler();
+        Schedulers.shutdown();
+
+        Task<?> task = Task.runAsync(() -> {
+            Thread.sleep(1000);
+        });
+
+        boolean result = task.test();
+
+        Assert.assertFalse("Task should fail since ExecutorService is shut down and RejectedExecutionException should be thrown", result);
+        Assert.assertTrue("RejectedExecutionException should be recorded", task.getException() instanceof RejectedExecutionException);
+    }
+}