001/*
002 * This file was downloaded on 2/21/2011 from http://svn.apache.org/viewvc/commons/proper/io/trunk/src/main/java/org/apache/commons/io/filefilter/RegexFileFilter.java?view=co
003 * 
004 * It is subject to the ASL 2.0 (see below).
005 * 
006 * The following changes were made from the original file:
007 * - the package name was changed
008 * - a default serialVersionUID was added
009 * - the accept matches returns the value of matcher.find() rather than matcher.matches()
010 */
011
012/*
013 * Licensed to the Apache Software Foundation (ASF) under one or more
014 * contributor license agreements.  See the NOTICE file distributed with
015 * this work for additional information regarding copyright ownership.
016 * The ASF licenses this file to You under the Apache License, Version 2.0
017 * (the "License"); you may not use this file except in compliance with
018 * the License.  You may obtain a copy of the License at
019 * 
020 *      http://www.apache.org/licenses/LICENSE-2.0
021 * 
022 * Unless required by applicable law or agreed to in writing, software
023 * distributed under the License is distributed on an "AS IS" BASIS,
024 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
025 * See the License for the specific language governing permissions and
026 * limitations under the License.
027 */
028package org.cleartk.util.cr;
029
030import java.io.File;
031import java.io.Serializable;
032import java.util.regex.Pattern;
033
034import org.apache.commons.io.IOCase;
035import org.apache.commons.io.filefilter.AbstractFileFilter;
036
037/**
038 * Filters files using supplied regular expression(s).
039 * <p/>
040 * See java.util.regex.Pattern for regex matching rules
041 * <p/>
042 * 
043 * <p/>
044 * e.g.
045 * 
046 * <pre>
047 * File dir = new File(&quot;.&quot;);
048 * FileFilter fileFilter = new RegexFileFilter(&quot;&circ;.*[tT]est(-\\d+)?\\.java$&quot;);
049 * File[] files = dir.listFiles(fileFilter);
050 * for (int i = 0; i &lt; files.length; i++) {
051 *   System.out.println(files[i]);
052 * }
053 * </pre>
054 * 
055 * @author Oliver Siegmar
056 * @version $Revision$
057 * @since Commons IO 1.4
058 */
059public class RegexFileFilter extends AbstractFileFilter implements Serializable {
060
061  /**
062   * 
063   */
064  private static final long serialVersionUID = 1L;
065
066  /** The regular expression pattern that will be used to match filenames */
067  private final Pattern pattern;
068
069  /**
070   * Construct a new regular expression filter.
071   * 
072   * @param pattern
073   *          regular string expression to match
074   * @throws IllegalArgumentException
075   *           if the pattern is null
076   */
077  public RegexFileFilter(String pattern) {
078    if (pattern == null) {
079      throw new IllegalArgumentException("Pattern is missing");
080    }
081
082    this.pattern = Pattern.compile(pattern);
083  }
084
085  /**
086   * Construct a new regular expression filter with the specified flags case sensitivity.
087   * 
088   * @param pattern
089   *          regular string expression to match
090   * @param caseSensitivity
091   *          how to handle case sensitivity, null means case-sensitive
092   * @throws IllegalArgumentException
093   *           if the pattern is null
094   */
095  public RegexFileFilter(String pattern, IOCase caseSensitivity) {
096    if (pattern == null) {
097      throw new IllegalArgumentException("Pattern is missing");
098    }
099    int flags = 0;
100    if (caseSensitivity != null && !caseSensitivity.isCaseSensitive()) {
101      flags = Pattern.CASE_INSENSITIVE;
102    }
103    this.pattern = Pattern.compile(pattern, flags);
104  }
105
106  /**
107   * Construct a new regular expression filter with the specified flags.
108   * 
109   * @param pattern
110   *          regular string expression to match
111   * @param flags
112   *          pattern flags - e.g. {@link Pattern#CASE_INSENSITIVE}
113   * @throws IllegalArgumentException
114   *           if the pattern is null
115   */
116  public RegexFileFilter(String pattern, int flags) {
117    if (pattern == null) {
118      throw new IllegalArgumentException("Pattern is missing");
119    }
120    this.pattern = Pattern.compile(pattern, flags);
121  }
122
123  /**
124   * Construct a new regular expression filter for a compiled regular expression
125   * 
126   * @param pattern
127   *          regular expression to match
128   * @throws IllegalArgumentException
129   *           if the pattern is null
130   */
131  public RegexFileFilter(Pattern pattern) {
132    if (pattern == null) {
133      throw new IllegalArgumentException("Pattern is missing");
134    }
135
136    this.pattern = pattern;
137  }
138
139  /**
140   * Checks to see if the filename matches one of the regular expressions.
141   * 
142   * @param dir
143   *          the file directory
144   * @param name
145   *          the filename
146   * @return true if the filename matches one of the regular expressions
147   */
148  @Override
149  public boolean accept(File dir, String name) {
150    return (pattern.matcher(name).find());
151  }
152
153}