Add comments to FileUtils and IOUtils

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

@@ -225,16 +225,16 @@ public class LibraryDownloadTask extends Task {
         int x = decompressed.length;
         int len = decompressed[(x - 8)] & 0xFF | (decompressed[(x - 7)] & 0xFF) << 8 | (decompressed[(x - 6)] & 0xFF) << 16 | (decompressed[(x - 5)] & 0xFF) << 24;
 
-        File temp = FileUtils.createTempFile("minecraft", ".pack");
+        Path temp = Files.createTempFile("minecraft", ".pack");
 
         byte[] checksums = Arrays.copyOfRange(decompressed, decompressed.length - len - 8, decompressed.length - 8);
 
-        OutputStream out = new FileOutputStream(temp);
+        try (OutputStream out = Files.newOutputStream(temp)) {
             out.write(decompressed, 0, decompressed.length - len - 8);
-        out.close();
+        }
 
         try (FileOutputStream jarBytes = new FileOutputStream(dest); JarOutputStream jos = new JarOutputStream(jarBytes)) {
-            Pack200.newUnpacker().unpack(temp, jos);
+            Pack200.newUnpacker().unpack(temp.toFile(), jos);
 
             JarEntry checksumsFile = new JarEntry("checksums.sha1");
             checksumsFile.setTime(0L);
@@ -243,6 +243,6 @@ public class LibraryDownloadTask extends Task {
             jos.closeEntry();
         }
 
-        temp.delete();
+        Files.delete(temp);
     }
 }

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

@@ -53,8 +53,6 @@ public final class VersionJsonSaveTask extends TaskResult<Version> {
     @Override
     public void execute() throws Exception {
         File json = repository.getVersionJson(version.getId()).getAbsoluteFile();
-        if (!FileUtils.makeFile(json))
-            throw new IOException("Cannot create file " + json);
         FileUtils.writeText(json, JsonUtils.GSON.toJson(version));
     }
 }

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

@@ -168,8 +168,8 @@ public class DefaultGameRepository implements GameRepository {
 
         versions.remove(id);
 
-        if (FileUtils.isMovingToTrashSupported()) {
+        if (FileUtils.isMovingToTrashSupported() && FileUtils.moveToTrash(removedFile)) {
-            return FileUtils.moveToTrash(removedFile);
+            return true;
         }
 
         // remove json files first to ensure HMCL will not recognize this folder as a valid version.

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

@@ -23,7 +23,7 @@ import com.google.gson.reflect.TypeToken;
 import org.jackhuang.hmcl.util.*;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 import org.jackhuang.hmcl.util.io.CompressingUtils;
-import org.jackhuang.hmcl.util.io.IOUtils;
+import org.jackhuang.hmcl.util.io.FileUtils;
 
 import java.io.File;
 import java.io.IOException;
@@ -119,7 +119,7 @@ public final class ForgeModMetadata {
             Path mcmod = fs.getPath("mcmod.info");
             if (Files.notExists(mcmod))
                 throw new IOException("File " + modFile + " is not a Forge mod.");
-            List<ForgeModMetadata> modList = JsonUtils.GSON.fromJson(IOUtils.readFullyAsString(Files.newInputStream(mcmod)),
+            List<ForgeModMetadata> modList = JsonUtils.GSON.fromJson(FileUtils.readText(mcmod),
                     new TypeToken<List<ForgeModMetadata>>() {
                     }.getType());
             if (modList == null || modList.isEmpty())

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

@@ -33,6 +33,7 @@ import java.io.RandomAccessFile;
 import java.math.BigInteger;
 import java.net.HttpURLConnection;
 import java.net.URL;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.security.MessageDigest;
 import java.util.Optional;
@@ -212,7 +213,7 @@ public class FileDownloadTask extends Task {
                 break;
             }
 
-            File temp = null;
+            Path temp = null;
 
             try {
                 updateProgress(0);
@@ -242,15 +243,15 @@ public class FileDownloadTask extends Task {
                 if (!FileUtils.makeDirectory(file.getAbsoluteFile().getParentFile()))
                     throw new IOException("Could not make directory " + file.getAbsoluteFile().getParent());
 
-                temp = FileUtils.createTempFile();
+                temp = Files.createTempFile(null, null);
-                rFile = new RandomAccessFile(temp, "rw");
+                rFile = new RandomAccessFile(temp.toFile(), "rw");
 
                 MessageDigest digest = integrityCheck == null ? null : integrityCheck.createDigest();
 
                 stream = con.getInputStream();
                 int lastDownloaded = 0, downloaded = 0;
                 long lastTime = System.currentTimeMillis();
-                byte buffer[] = new byte[IOUtils.DEFAULT_BUFFER_SIZE];
+                byte[] buffer = new byte[IOUtils.DEFAULT_BUFFER_SIZE];
                 while (true) {
                     if (Thread.interrupted()) {
                         Thread.currentThread().interrupt();
@@ -283,16 +284,15 @@ public class FileDownloadTask extends Task {
 
                 // Restore temp file to original name.
                 if (Thread.interrupted()) {
-                    temp.delete();
+                    temp.toFile().delete();
                     Thread.currentThread().interrupt();
                     break;
                 } else {
-                    if (file.exists() && !file.delete())
+                    Files.deleteIfExists(file.toPath());
-                        throw new IOException("Unable to delete existent file " + file);
                     if (!FileUtils.makeDirectory(file.getAbsoluteFile().getParentFile()))
                         throw new IOException("Unable to make parent directory " + file);
                     try {
-                        FileUtils.moveFile(temp, file);
+                        FileUtils.moveFile(temp.toFile(), file);
                     } catch (Exception e) {
                         throw new IOException("Unable to move temp file from " + temp + " to " + file, e);
                     }
@@ -321,7 +321,7 @@ public class FileDownloadTask extends Task {
                 return;
             } catch (IOException | IllegalStateException e) {
                 if (temp != null)
-                    temp.delete();
+                    temp.toFile().delete();
                 exception = e;
             } finally {
                 closeFiles();

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

@@ -293,6 +293,11 @@ public abstract class Task {
         return new TaskResult<R>() {
             TaskResult<R> then;
 
+            @Override
+            public Collection<? extends Task> getDependents() {
+                return Collections.singleton(Task.this);
+            }
+
             @Override
             public void execute() throws Exception {
                 then = taskSupplier.get().storeTo(this::setResult);

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

@@ -116,14 +116,43 @@ public final class FileUtils {
         return new String(Files.readAllBytes(file), charset);
     }
 
+    /**
+     * Write plain text to file. Characters are encoded into bytes using UTF-8.
+     *
+     * We don't care about platform difference of line separator. Because readText accept all possibilities of line separator.
+     * It will create the file if it does not exist, or truncate the existing file to empty for rewriting.
+     * All characters in text will be written into the file in binary format. Existing data will be erased.
+     * @param file the path to the file
+     * @param text the text being written to file
+     * @throws IOException if an I/O error occurs
+     */
     public static void writeText(File file, String text) throws IOException {
         writeText(file, text, UTF_8);
     }
 
+    /**
+     * Write plain text to file.
+     *
+     * We don't care about platform difference of line separator. Because readText accept all possibilities of line separator.
+     * It will create the file if it does not exist, or truncate the existing file to empty for rewriting.
+     * All characters in text will be written into the file in binary format. Existing data will be erased.
+     * @param file the path to the file
+     * @param text the text being written to file
+     * @param charset the charset to use for encoding
+     * @throws IOException if an I/O error occurs
+     */
     public static void writeText(File file, String text, Charset charset) throws IOException {
         writeBytes(file, text.getBytes(charset));
     }
 
+    /**
+     * Write byte array to file.
+     * It will create the file if it does not exist, or truncate the existing file to empty for rewriting.
+     * All bytes in byte array will be written into the file in binary format. Existing data will be erased.
+     * @param file the path to the file
+     * @param array the data being written to file
+     * @throws IOException if an I/O error occurs
+     */
     public static void writeBytes(File file, byte[] array) throws IOException {
         Files.createDirectories(file.toPath().getParent());
         Files.write(file.toPath(), array);
@@ -153,6 +182,14 @@ public final class FileUtils {
         }
     }
 
+    /**
+     * Copy directory.
+     * Paths of all files relative to source directory will be the same as the ones relative to destination directory.
+     *
+     * @param src the source directory.
+     * @param dest the destination directory, which will be created if not existing.
+     * @throws IOException if an I/O error occurs.
+     */
     public static void copyDirectory(Path src, Path dest) throws IOException {
         Files.walkFileTree(src, new SimpleFileVisitor<Path>(){
             @Override
@@ -173,6 +210,20 @@ public final class FileUtils {
         });
     }
 
+    /**
+     * Move file to trash.
+     *
+     * This method is only implemented in Java 9. Please check we are using Java 9 by invoking isMovingToTrashSupported.
+     * Example:
+     * <pre>{@code
+     * if (FileUtils.isMovingToTrashSupported()) {
+     *     FileUtils.moveToTrash(file);
+     * }
+     * }</pre>
+     * @param file the file being moved to trash.
+     * @see FileUtils#isMovingToTrashSupported()
+     * @return false if moveToTrash does not exist, or platform does not support Desktop.Action.MOVE_TO_TRASH
+     */
     public static boolean moveToTrash(File file) {
         try {
             java.awt.Desktop desktop = java.awt.Desktop.getDesktop();
@@ -314,20 +365,4 @@ public final class FileUtils {
                     result.add(it);
         return result;
     }
-
-    public static File createTempFile() throws IOException {
-        return createTempFile("tmp");
-    }
-
-    public static File createTempFile(String prefix) throws IOException {
-        return createTempFile(prefix, null);
-    }
-
-    public static File createTempFile(String prefix, String suffix) throws IOException {
-        return createTempFile(prefix, suffix, null);
-    }
-
-    public static File createTempFile(String prefix, String suffix, File directory) throws IOException {
-        return File.createTempFile(prefix, suffix, directory);
-    }
 }

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

@@ -21,8 +21,9 @@ import java.io.*;
 import java.nio.charset.Charset;
 
 /**
+ * This utility class consists of some util methods operating on InputStream/OutputStream.
  *
- * @author huang
+ * @author huangyuhui
  */
 public final class IOUtils {
 
@@ -31,12 +32,26 @@ public final class IOUtils {
 
     public static final int DEFAULT_BUFFER_SIZE = 8 * 1024;
 
+    /**
+     * Read all bytes to a buffer from given input stream. The stream will not be closed.
+     *
+     * @param stream the InputStream being read.
+     * @return all bytes read from the stream
+     * @throws IOException if an I/O error occurs.
+     */
     public static byte[] readFullyWithoutClosing(InputStream stream) throws IOException {
         ByteArrayOutputStream result = new ByteArrayOutputStream();
         copyTo(stream, result);
         return result.toByteArray();
     }
 
+    /**
+     * Read all bytes to a buffer from given input stream, and close the input stream finally.
+     *
+     * @param stream the InputStream being read, closed finally.
+     * @return all bytes read from the stream
+     * @throws IOException if an I/O error occurs.
+     */
     public static ByteArrayOutputStream readFully(InputStream stream) throws IOException {
         try (InputStream is = stream) {
             ByteArrayOutputStream result = new ByteArrayOutputStream();