diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultCacheRepository.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultCacheRepository.java
index 540764de0..b00a5b736 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultCacheRepository.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultCacheRepository.java
@@ -63,7 +63,7 @@ public class DefaultCacheRepository extends CacheRepository {
         lock.writeLock().lock();
         try {
             if (Files.isRegularFile(indexFile))
-                index = JsonUtils.fromNonNullJson(FileUtils.readText(indexFile.toFile()), Index.class);
+                index = JsonUtils.fromNonNullJson(FileUtils.readText(indexFile), Index.class);
             else
                 index = new Index();
         } catch (IOException | JsonParseException e) {
@@ -180,7 +180,7 @@ public class DefaultCacheRepository extends CacheRepository {
             hash = DigestUtils.digestToString(SHA1, path);
 
         Path cache = getFile(SHA1, hash);
-        FileUtils.copyFile(path.toFile(), cache.toFile());
+        FileUtils.copyFile(path, cache);
 
         Lock writeLock = lock.writeLock();
         writeLock.lock();
@@ -198,7 +198,7 @@ public class DefaultCacheRepository extends CacheRepository {
     private void saveIndex() {
         if (indexFile == null || index == null) return;
         try {
-            FileUtils.writeText(indexFile.toFile(), JsonUtils.GSON.toJson(index));
+            FileUtils.writeText(indexFile, JsonUtils.GSON.toJson(index));
         } catch (IOException e) {
             Logging.LOG.log(Level.SEVERE, "Unable to save index.json", e);
         }
@@ -217,7 +217,7 @@ public class DefaultCacheRepository extends CacheRepository {
      *     // assets and versions will not be included in index.
      * }
      */
-    private class Index implements Validation {
+    private static final class Index implements Validation {
         private final Set<LibraryIndex> libraries;
 
         public Index() {
diff --git a/HMCLCore/src/main/java/org/jackhuang/hmcl/util/CacheRepository.java b/HMCLCore/src/main/java/org/jackhuang/hmcl/util/CacheRepository.java
index 9b68bc6fe..133ea1f32 100644
--- a/HMCLCore/src/main/java/org/jackhuang/hmcl/util/CacheRepository.java
+++ b/HMCLCore/src/main/java/org/jackhuang/hmcl/util/CacheRepository.java
@@ -27,7 +27,6 @@ import org.jackhuang.hmcl.util.io.IOUtils;
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.io.RandomAccessFile;
 import java.net.URLConnection;
 import java.nio.ByteBuffer;
 import java.nio.channels.Channels;
@@ -35,6 +34,7 @@ import java.nio.channels.FileChannel;
 import java.nio.channels.FileLock;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.*;
@@ -69,7 +69,7 @@ public class CacheRepository {
             }
 
             if (Files.isRegularFile(indexFile)) {
-                ETagIndex raw = JsonUtils.GSON.fromJson(FileUtils.readText(indexFile.toFile()), ETagIndex.class);
+                ETagIndex raw = JsonUtils.GSON.fromJson(FileUtils.readText(indexFile), ETagIndex.class);
                 if (raw == null)
                     index = new HashMap<>();
                 else
@@ -123,12 +123,12 @@ public class CacheRepository {
     public void tryCacheFile(Path path, String algorithm, String hash) throws IOException {
         Path cache = getFile(algorithm, hash);
         if (Files.isRegularFile(cache)) return;
-        FileUtils.copyFile(path.toFile(), cache.toFile());
+        FileUtils.copyFile(path, cache);
     }
 
     public Path cacheFile(Path path, String algorithm, String hash) throws IOException {
         Path cache = getFile(algorithm, hash);
-        FileUtils.copyFile(path.toFile(), cache.toFile());
+        FileUtils.copyFile(path, cache);
         return cache;
     }
 
@@ -222,7 +222,7 @@ public class CacheRepository {
         cacheData(() -> {
             String hash = DigestUtils.digestToString(SHA1, bytes);
             Path cached = getFile(SHA1, hash);
-            FileUtils.writeBytes(cached.toFile(), bytes);
+            FileUtils.writeBytes(cached, bytes);
             return new CacheResult(hash, cached);
         }, conn);
     }
@@ -287,7 +287,7 @@ public class CacheRepository {
     }
 
     public void saveETagIndex() throws IOException {
-        try (RandomAccessFile file = new RandomAccessFile(indexFile.toFile(), "rw"); FileChannel channel = file.getChannel()) {
+        try (FileChannel channel = FileChannel.open(indexFile, StandardOpenOption.READ, StandardOpenOption.WRITE)) {
             FileLock lock = channel.lock();
             try {
                 ETagIndex indexOnDisk = JsonUtils.fromMaybeMalformedJson(new String(IOUtils.readFullyWithoutClosing(Channels.newInputStream(channel)), UTF_8), ETagIndex.class);
@@ -371,7 +371,7 @@ public class CacheRepository {
     /**
      * Universal cache
      */
-    public static class Storage {
+    public static final class Storage {
         private final String name;
         private Map<String, Object> storage;
         private final ReadWriteLock lock = new ReentrantReadWriteLock();
@@ -409,7 +409,7 @@ public class CacheRepository {
             try {
                 indexFile = cacheDirectory.resolve(name + ".json");
                 if (Files.isRegularFile(indexFile)) {
-                    joinEntries(JsonUtils.fromNonNullJson(FileUtils.readText(indexFile.toFile()), new TypeToken<Map<String, Object>>() {
+                    joinEntries(JsonUtils.fromNonNullJson(FileUtils.readText(indexFile), new TypeToken<Map<String, Object>>() {
                     }.getType()));
                 }
             } catch (IOException | JsonParseException e) {
@@ -420,7 +420,7 @@ public class CacheRepository {
         }
 
         public void saveToFile() {
-            try (RandomAccessFile file = new RandomAccessFile(indexFile.toFile(), "rw"); FileChannel channel = file.getChannel()) {
+            try (FileChannel channel = FileChannel.open(indexFile, StandardOpenOption.READ, StandardOpenOption.WRITE)) {
                 FileLock lock = channel.lock();
                 try {
                     Map<String, Object> indexOnDisk = JsonUtils.fromMaybeMalformedJson(new String(IOUtils.readFullyWithoutClosing(Channels.newInputStream(channel)), UTF_8), new TypeToken<Map<String, Object>>() {