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 org.apache.commons.vfs2.FileName;
20 import org.apache.commons.vfs2.FileObject;
21 import org.apache.commons.vfs2.FileSystem;
22
23 /**
24 * A {@link org.apache.commons.vfs2.FilesCache} implementation.
25 * <p>
26 * This implementation never ever caches a single file.
27 * </p>
28 * <p>
29 * <strong>Notice</strong>: if you use resolveFile(uri) multiple times with the same path, the system will always create a new
30 * instance. Changes on one instance of this file are not seen by the others.
31 * </p>
32 */
33 public class NullFilesCache extends AbstractFilesCache {
34
35 /**
36 * Constructs a new instance.
37 */
38 public NullFilesCache() {
39 // empty
40 }
41
42 @Override
43 public void clear(final FileSystem filesystem) {
44 // empty
45 }
46
47 @Override
48 public FileObject getFile(final FileSystem filesystem, final FileName name) {
49 return null;
50 }
51
52 @Override
53 public void putFile(final FileObject file) {
54 // empty
55 }
56
57 @Override
58 public boolean putFileIfAbsent(final FileObject file) {
59 return false;
60 }
61
62 @Override
63 public void removeFile(final FileSystem filesystem, final FileName name) {
64 // empty
65 }
66 }