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 import java.io.Serializable;
21 import java.util.regex.Pattern;
22
23 import org.apache.commons.io.IOCase;
24
25 /**
26 * Filters files using supplied regular expression(s).
27 * <p/>
28 * See java.util.regex.Pattern for regex matching rules
29 * <p/>
30 *
31 * <p/>
32 * e.g.
33 * <pre>
34 * File dir = new File(".");
35 * FileFilter fileFilter = new RegexFileFilter("^.*[tT]est(-\\d+)?\\.java$");
36 * File[] files = dir.listFiles(fileFilter);
37 * for (int i = 0; i < files.length; i++) {
38 * System.out.println(files[i]);
39 * }
40 * </pre>
41 *
42 * @author Oliver Siegmar
43 * @version $Revision: 606381 $
44 * @since Commons IO 1.4
45 */
46 public class RegexFileFilter extends AbstractFileFilter implements Serializable {
47
48 /** The regular expression pattern that will be used to match filenames */
49 private final Pattern pattern;
50
51 /**
52 * Construct a new regular expression filter.
53 *
54 * @param pattern regular string expression to match
55 * @throws IllegalArgumentException if the pattern is null
56 */
57 public RegexFileFilter(String pattern) {
58 if (pattern == null) {
59 throw new IllegalArgumentException("Pattern is missing");
60 }
61
62 this.pattern = Pattern.compile(pattern);
63 }
64
65 /**
66 * Construct a new regular expression filter with the specified flags case sensitivity.
67 *
68 * @param pattern regular string expression to match
69 * @param caseSensitivity how to handle case sensitivity, null means case-sensitive
70 * @throws IllegalArgumentException if the pattern is null
71 */
72 public RegexFileFilter(String pattern, IOCase caseSensitivity) {
73 if (pattern == null) {
74 throw new IllegalArgumentException("Pattern is missing");
75 }
76 int flags = 0;
77 if (caseSensitivity != null && !caseSensitivity.isCaseSensitive()) {
78 flags = Pattern.CASE_INSENSITIVE;
79 }
80 this.pattern = Pattern.compile(pattern, flags);
81 }
82
83 /**
84 * Construct a new regular expression filter with the specified flags.
85 *
86 * @param pattern regular string expression to match
87 * @param flags pattern flags - e.g. {@link Pattern#CASE_INSENSITIVE}
88 * @throws IllegalArgumentException if the pattern is null
89 */
90 public RegexFileFilter(String pattern, int flags) {
91 if (pattern == null) {
92 throw new IllegalArgumentException("Pattern is missing");
93 }
94 this.pattern = Pattern.compile(pattern, flags);
95 }
96
97 /**
98 * Construct a new regular expression filter for a compiled regular expression
99 *
100 * @param pattern regular expression to match
101 * @throws IllegalArgumentException if the pattern is null
102 */
103 public RegexFileFilter(Pattern pattern) {
104 if (pattern == null) {
105 throw new IllegalArgumentException("Pattern is missing");
106 }
107
108 this.pattern = pattern;
109 }
110
111 /**
112 * Checks to see if the filename matches one of the regular expressions.
113 *
114 * @param dir the file directory
115 * @param name the filename
116 * @return true if the filename matches one of the regular expressions
117 */
118 public boolean accept(File dir, String name) {
119 return (pattern.matcher(name).matches());
120 }
121
122 }