1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.vfs2.cache;
18
19 import java.lang.ref.Reference;
20 import java.lang.ref.ReferenceQueue;
21 import java.lang.ref.WeakReference;
22
23 import org.apache.commons.vfs2.FileObject;
24
25 /**
26 * This implementation caches every file as long as it is strongly reachable by the Java vm. As soon as the object is no
27 * longer reachable it will be discarded. In contrast to the SoftRefFilesCache this implementation might free resources
28 * faster as it doesn't wait until a memory limitation.
29 *
30 * @see java.lang.ref.WeakReference
31 */
32 public class WeakRefFilesCache extends SoftRefFilesCache {
33
34 /**
35 * Constructs a new instance.
36 */
37 public WeakRefFilesCache() {
38 // empty
39 }
40
41 @Override
42 protected Reference<FileObject> createReference(final FileObject file, final ReferenceQueue<FileObject> refqueue) {
43 return new WeakReference<>(file, refqueue);
44 }
45 }