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.io.filefilter;
18
19 import java.io.File;
20
21 /**
22 * This filter accepts <code>File</code>s that are directories.
23 * <p>
24 * For example, here is how to print out a list of the
25 * current directory's subdirectories:
26 *
27 * <pre>
28 * File dir = new File(".");
29 * String[] files = dir.list( DirectoryFileFilter.INSTANCE );
30 * for ( int i = 0; i < files.length; i++ ) {
31 * System.out.println(files[i]);
32 * }
33 * </pre>
34 *
35 * @since Commons IO 1.0
36 * @version $Revision: 471628 $ $Date: 2006-11-06 05:06:45 +0100 (Mo, 06 Nov 2006) $
37 *
38 * @author Stephen Colebourne
39 * @author Peter Donald
40 */
41 public class DirectoryFileFilter extends AbstractFileFilter {
42
43 /**
44 * Singleton instance of directory filter.
45 * @since Commons IO 1.3
46 */
47 public static final IOFileFilter DIRECTORY = new DirectoryFileFilter();
48 /**
49 * Singleton instance of directory filter.
50 * Please use the identical DirectoryFileFilter.DIRECTORY constant.
51 * The new name is more JDK 1.5 friendly as it doesn't clash with other
52 * values when using static imports.
53 */
54 public static final IOFileFilter INSTANCE = DIRECTORY;
55
56 /**
57 * Restrictive consructor.
58 */
59 protected DirectoryFileFilter() {
60 }
61
62 /**
63 * Checks to see if the file is a directory.
64 *
65 * @param file the File to check
66 * @return true if the file is a directory
67 */
68 public boolean accept(File file) {
69 return file.isDirectory();
70 }
71
72 }