You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@commons.apache.org by im...@apache.org on 2007/05/14 20:17:53 UTC

svn commit: r537930 - in /jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs: provider/DelegateFileObject.java util/WeakRefFileListener.java

Author: imario
Date: Mon May 14 11:17:52 2007
New Revision: 537930

URL: http://svn.apache.org/viewvc?view=rev&rev=537930
Log:
VFS-143: Fix memory leak in DelegateFileObject in it's handling of listeners - Thanks to Adam Heath for the patch!

Added:
    jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/util/WeakRefFileListener.java
Modified:
    jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/provider/DelegateFileObject.java

Modified: jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/provider/DelegateFileObject.java
URL: http://svn.apache.org/viewvc/jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/provider/DelegateFileObject.java?view=diff&rev=537930&r1=537929&r2=537930
==============================================================================
--- jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/provider/DelegateFileObject.java (original)
+++ jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/provider/DelegateFileObject.java Mon May 14 11:17:52 2007
@@ -22,6 +22,7 @@
 import org.apache.commons.vfs.FileObject;
 import org.apache.commons.vfs.FileSystemException;
 import org.apache.commons.vfs.FileType;
+import org.apache.commons.vfs.util.WeakRefFileListener;
 
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -54,7 +55,7 @@
         this.file = file;
         if (file != null)
         {
-            file.getFileSystem().addListener(file, this);
+			WeakRefFileListener.installListener(file, this);
         }
     }
 
@@ -80,7 +81,7 @@
 
         if (file != null)
         {
-            file.getFileSystem().addListener(file, this);
+			WeakRefFileListener.installListener(file, this);
         }
         this.file = file;
         maybeTypeChanged(oldType);
@@ -296,6 +297,7 @@
      */
     public void fileCreated(final FileChangeEvent event) throws Exception
     {
+        if (event.getFile() != file) return;
         if (!ignoreEvent)
         {
             handleCreate(file.getType());
@@ -307,6 +309,7 @@
      */
     public void fileDeleted(final FileChangeEvent event) throws Exception
     {
+        if (event.getFile() != file) return;
         if (!ignoreEvent)
         {
             handleDelete();
@@ -320,6 +323,7 @@
      */
     public void fileChanged(FileChangeEvent event) throws Exception
     {
+        if (event.getFile() != file) return;
         if (!ignoreEvent)
         {
             handleChanged();

Added: jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/util/WeakRefFileListener.java
URL: http://svn.apache.org/viewvc/jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/util/WeakRefFileListener.java?view=auto&rev=537930
==============================================================================
--- jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/util/WeakRefFileListener.java (added)
+++ jakarta/commons/proper/vfs/trunk/core/src/main/java/org/apache/commons/vfs/util/WeakRefFileListener.java Mon May 14 11:17:52 2007
@@ -0,0 +1,111 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.vfs.util;
+
+import org.apache.commons.vfs.FileChangeEvent;
+import org.apache.commons.vfs.FileListener;
+import org.apache.commons.vfs.FileName;
+import org.apache.commons.vfs.FileObject;
+import org.apache.commons.vfs.FileSystem;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * Wrap a listener with a WeakReference.
+ *
+ * @author <a href="mailto:doogie@brainfood.com">Adam Heath</a>
+ * @version $Revision: 262 $ $Date: 2006-12-20T09:14:53.055649Z $
+ */
+public class WeakRefFileListener implements FileListener
+{
+	private final FileSystem fs;
+	private final FileName name;
+	private final WeakReference listener;
+
+	protected WeakRefFileListener(final FileObject file, final FileListener listener)
+	{
+		this.fs = file.getFileSystem();
+		this.name = file.getName();
+		this.listener = new WeakReference(listener);
+	}
+
+	/**
+	 * This will install the <code>listener<code> at the given <code>file</code>
+	 */
+	public static void installListener(final FileObject file, final FileListener listener)
+	{
+		WeakRefFileListener weakListener = new WeakRefFileListener(file, listener);
+		
+		file.getFileSystem().addListener(file, new WeakRefFileListener(file, weakListener));
+	}
+
+	/**
+	 * returns the wrapped listener. If it is gone, the WeakRefFileListener wrapper will
+	 * remove itself from the list of listeners.
+	 */
+	protected FileListener getListener() throws Exception
+	{
+		FileListener listener = (FileListener) this.listener.get();
+		if (listener == null)
+		{
+			FileObject file = fs.resolveFile(name);
+			file.getFileSystem().removeListener(file, this);
+		}
+		return listener;
+	}
+
+	/**
+	 * Called when a file is created.
+	 */
+	public void fileCreated(final FileChangeEvent event) throws Exception
+	{
+		FileListener listener = getListener();
+		if (listener == null)
+		{
+			return;
+		}
+		listener.fileCreated(event);
+	}
+
+	/**
+	 * Called when a file is deleted.
+	 */
+	public void fileDeleted(final FileChangeEvent event) throws Exception
+	{
+		FileListener listener = getListener();
+		if (listener == null)
+		{
+			return;
+		}
+		listener.fileDeleted(event);
+	}
+
+	/**
+	 * Called when a file is changed.
+	 * <p/>
+	 * This will only happen if you monitor the file using {@link org.apache.commons.vfs.FileMonitor}.
+	 */
+	public void fileChanged(FileChangeEvent event) throws Exception
+	{
+		FileListener listener = getListener();
+		if (listener == null)
+		{
+			return;
+		}
+		listener.fileChanged(event);
+	}
+}



---------------------------------------------------------------------
To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
For additional commands, e-mail: commons-dev-help@jakarta.apache.org