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 } 123
