remove lastException in task.variables

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

@@ -69,7 +69,7 @@ public class DefaultGameBuilder extends GameBuilder {
                 result = result.then(dependencyManager.installLibraryAsync(remoteVersion));
 
             return result;
-        }).finalized((variables, isDependentsSucceeded) -> {
+        }).finalized((variables, isDependentsSucceeded, exception) -> {
             if (!isDependentsSucceeded)
                 dependencyManager.getGameRepository().getVersionRoot(name).delete();
         });

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

@@ -20,5 +20,5 @@ package org.jackhuang.hmcl.task;
 import org.jackhuang.hmcl.util.AutoTypingMap;
 
 public interface FinalizedCallback {
-    void execute(AutoTypingMap<String> variables, boolean isDependentsSucceeded) throws Exception;
+    void execute(AutoTypingMap<String> variables, boolean isDependentsSucceeded, Exception exception) throws Exception;
 }

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

@@ -27,7 +27,7 @@ import java.util.Collections;
  */
 final class FinalizedTask extends Task {
 
-    private final Collection<Task> dependents;
+    private final Task pred;
     private final FinalizedCallback callback;
     private final Scheduler scheduler;
 
@@ -38,7 +38,7 @@ final class FinalizedTask extends Task {
      * @param callback 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.
      */
     public FinalizedTask(Task pred, Scheduler scheduler, FinalizedCallback callback, String name) {
-        this.dependents = Collections.singleton(pred);
+        this.pred = pred;
         this.scheduler = scheduler;
         this.callback = callback;
 
@@ -53,7 +53,7 @@ final class FinalizedTask extends Task {
 
     @Override
     public void execute() throws Exception {
-        callback.execute(getVariables(), isDependentsSucceeded());
+        callback.execute(getVariables(), isDependentsSucceeded(), pred.getLastException());
 
         if (!isDependentsSucceeded())
             throw new SilentException();
@@ -61,7 +61,7 @@ final class FinalizedTask extends Task {
 
     @Override
     public Collection<Task> getDependents() {
-        return dependents;
+        return Collections.singleton(pred);
     }
 
     @Override

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

@@ -68,13 +68,13 @@ public abstract class Task {
         this.state = state;
     }
 
-    private Throwable lastException = null;
+    private Exception lastException;
 
-    public Throwable getLastException() {
+    public Exception getLastException() {
         return lastException;
     }
 
-    void setLastException(Throwable e) {
+    void setLastException(Exception e) {
         lastException = e;
     }
 
@@ -321,7 +321,7 @@ public abstract class Task {
     }
 
     public final <T extends Exception, K extends Exception> Task finalized(Scheduler scheduler, ExceptionalConsumer<AutoTypingMap<String>, T> success, ExceptionalConsumer<Exception, K> failure) {
-        return finalized(scheduler, (variables, isDependentsSucceeded) -> {
+        return finalized(scheduler, (variables, isDependentsSucceeded, exception) -> {
             if (isDependentsSucceeded) {
                 if (success != null)
                     try {
@@ -331,10 +331,9 @@ public abstract class Task {
                         if (failure != null)
                             failure.accept(e);
                     }
-            }
-            else {
+            } else {
                 if (failure != null)
-                    failure.accept(variables.get(TaskExecutor.LAST_EXCEPTION_ID));
+                    failure.accept(exception);
             }
         });
     }

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

@@ -234,7 +234,6 @@ public final class TaskExecutor {
         } catch (Exception e) {
             task.setLastException(e);
             lastException = e;
-            variables.set(LAST_EXCEPTION_ID, e);
             if (task.getSignificance().shouldLog()) {
                 Logging.LOG.log(Level.FINE, "Task failed: " + task.getName(), e);
             }
@@ -279,6 +278,4 @@ public final class TaskExecutor {
         }
 
     }
-
-    public static final String LAST_EXCEPTION_ID = "lastException";
 }

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

@@ -61,7 +61,7 @@ public abstract class TaskResult<V> extends Task {
 
     public Task finalizedResult(Scheduler scheduler, FinalizedCallback<V> callback) {
         return new FinalizedTask(this, scheduler,
-                (variables, isDependentsSucceeded) -> callback.execute(getResult(), isDependentsSucceeded),
+                (variables, isDependentsSucceeded, exception) -> callback.execute(getResult(), isDependentsSucceeded, exception),
                 ReflectionHelper.getCaller().toString());
     }
 
@@ -98,6 +98,6 @@ public abstract class TaskResult<V> extends Task {
     }
 
     public interface FinalizedCallback<V> {
-        void execute(V result, boolean isDependentsSucceeded) throws Exception;
+        void execute(V result, boolean isDependentsSucceeded, Exception exception) throws Exception;
     }
 }

HMCLCore/src/main/java/org/jackhuang/hmcl/util/gson/Validation.java

@@ -35,6 +35,7 @@ public interface Validation {
      * Throw an exception when values are malformed.
      *
      * @throws JsonParseException if fields are filled in wrong format or wrong type.
+     * @throws TolerableValidationException if we want to replace this object with null (i.e. the object does not fulfill the constraints).
      */
     void validate() throws JsonParseException, TolerableValidationException;
 }