001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.vfs2.cache;
018    
019    import java.lang.ref.Reference;
020    import java.lang.ref.ReferenceQueue;
021    import java.lang.ref.WeakReference;
022    
023    import org.apache.commons.vfs2.FileObject;
024    
025    /**
026     * This implementation caches every file as long as it is strongly reachable by
027     * the java vm. As soon as the object is no longer reachable it will be discarded.
028     * In contrast to the SoftRefFilesCache this implementation might free resources faster
029     * as it don't wait until a memory limitation.
030     *
031     * @author <a href="http://commons.apache.org/vfs/team-list.html">Commons VFS team</a>
032     *          2005) $
033     * @see java.lang.ref.WeakReference
034     */
035    public class WeakRefFilesCache extends SoftRefFilesCache
036    {
037        @Override
038        protected Reference<FileObject> createReference(FileObject file, ReferenceQueue<FileObject> refqueue)
039        {
040            return new WeakReference<FileObject>(file, refqueue);
041        }
042    }