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 import java.util.regex.Pattern;
21
22 import org.apache.commons.vfs2.FileFilter;
23 import org.apache.commons.vfs2.FileSelectInfo;
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 * For example, to retrieve and print all java files where the name matched the
33 * regular expression in the current directory:
34 * </p>
35 *
36 * <pre>
37 * FileSystemManager fsManager = VFS.getManager();
38 * FileObject dir = fsManager.toFileObject(new File("."));
39 * FileObject[] files = dir.findFiles(new FileFilterSelector(new RegexFileFilter("ˆ.*[tT]est(-\\d+)?\\.java$")));
40 * for (int i = 0; i < files.length; i++) {
41 * System.out.println(files[i]);
42 * }
43 * </pre>
44 *
45 * @author This code was originally ported from Apache Commons IO File Filter
46 * @see "http://commons.apache.org/proper/commons-io/"
47 * @since 2.4
48 */
49 public class RegexFileFilter implements FileFilter, Serializable {
50
51 private static final long serialVersionUID = 1L;
52
53 /** Exception message when no pattern is given in the constructor. */
54 public static final String PATTERN_IS_MISSING = "Pattern is missing";
55
56 /** The regular expression pattern that will be used to match file names. */
57 private final Pattern pattern;
58
59 /**
60 * Construct a new regular expression filter for a compiled regular expression.
61 *
62 * @param pattern regular expression to match - Cannot be null
63 */
64 public RegexFileFilter(final Pattern pattern) {
65 if (pattern == null) {
66 throw new IllegalArgumentException(PATTERN_IS_MISSING);
67 }
68
69 this.pattern = pattern;
70 }
71
72 /**
73 * Construct a new regular expression filter.
74 *
75 * @param pattern regular string expression to match - Cannot be null
76 */
77 public RegexFileFilter(final String pattern) {
78 if (pattern == null) {
79 throw new IllegalArgumentException(PATTERN_IS_MISSING);
80 }
81
82 this.pattern = Pattern.compile(pattern);
83 }
84
85 /**
86 * Construct a new regular expression filter with the specified flags.
87 *
88 * @param pattern regular string expression to match
89 * @param flags pattern flags - e.g. {@link Pattern#CASE_INSENSITIVE}
90 */
91 public RegexFileFilter(final String pattern, final int flags) {
92 if (pattern == null) {
93 throw new IllegalArgumentException(PATTERN_IS_MISSING);
94 }
95 this.pattern = Pattern.compile(pattern, flags);
96 }
97
98 /**
99 * Construct a new regular expression filter with the specified flags case
100 * sensitivity.
101 *
102 * @param pattern regular string expression to match - Cannot be null
103 * @param caseSensitivity how to handle case sensitivity, null means
104 * case-sensitive
105 */
106 public RegexFileFilter(final String pattern, final IOCase caseSensitivity) {
107 if (pattern == null) {
108 throw new IllegalArgumentException(PATTERN_IS_MISSING);
109 }
110 int flags = 0;
111 if (caseSensitivity != null && !caseSensitivity.isCaseSensitive()) {
112 flags = Pattern.CASE_INSENSITIVE;
113 }
114 this.pattern = Pattern.compile(pattern, flags);
115 }
116
117 /**
118 * Checks to see if the file name matches one of the regular expressions.
119 *
120 * @param fileSelectInfo the File to check
121 *
122 * @return true if the file matches one of the regular expressions
123 */
124 @Override
125 public boolean accept(final FileSelectInfo fileSelectInfo) {
126 final String name = fileSelectInfo.getFile().getName().getBaseName();
127 return pattern.matcher(name).matches();
128 }
129
130 }