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.filter;
18
19 import java.io.Serializable;
20
21 import org.apache.commons.vfs2.FileFilter;
22 import org.apache.commons.vfs2.FileSelectInfo;
23 import org.apache.commons.vfs2.FileSystemException;
24 import org.apache.commons.vfs2.FileType;
25
26 /**
27 * This filter accepts {@code File}s that are directories.
28 * <p>
29 * For example, here is how to print out a list of the current directory's sub
30 * directories:
31 * </p>
32 *
33 * <pre>
34 * FileSystemManager fsManager = VFS.getManager();
35 * FileObject dir = fsManager.toFileObject(new File("."));
36 * FileObject[] files = dir.findFiles(new FileFilterSelector(DirectoryFileFilter.DIRECTORY));
37 * for (int i = 0; i < files.length; i++) {
38 * System.out.println(files[i]);
39 * }
40 * </pre>
41 *
42 * @author This code was originally ported from Apache Commons IO File Filter
43 * @see "https://commons.apache.org/proper/commons-io/"
44 * @since 2.4
45 */
46 public class DirectoryFileFilter implements FileFilter, Serializable {
47
48 /**
49 * Singleton instance of directory filter.
50 */
51 public static final FileFilter DIRECTORY = new DirectoryFileFilter();
52
53 private static final long serialVersionUID = 1L;
54
55 /**
56 * Restrictive constructor.
57 */
58 protected DirectoryFileFilter() {
59 }
60
61 /**
62 * Checks to see if the file is a directory.
63 *
64 * @param fileSelectInfo the File to check
65 * @return {@code true} if the file is a directory
66 * @throws FileSystemException Thrown for file system errors.
67 */
68 @Override
69 public boolean accept(final FileSelectInfo fileSelectInfo) throws FileSystemException {
70 return fileSelectInfo.getFile().getType() == FileType.FOLDER;
71 }
72
73 }