001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2008-2012 SonarSource
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    
021    package net.sourceforge.pmd.util;
022    
023    import java.io.File;
024    import java.io.FilenameFilter;
025    import java.util.ArrayList;
026    import java.util.List;
027    
028    /**
029     * A utility class for finding files within a directory.
030     */
031    public class FileFinder {
032    
033      private FilenameFilter filter;
034      private static final String FILE_SEP = System.getProperty("file.separator");
035    
036      public List<File> findFilesFrom(String dir, FilenameFilter filter, boolean recurse) {
037        this.filter = filter;
038        List<File> files = new ArrayList<File>();
039        scanDirectory(new File(dir), files, recurse);
040        return files;
041      }
042    
043      /**
044       * Implements a tail recursive file scanner
045       */
046      private void scanDirectory(File dir, List<File> list, boolean recurse) {
047        String[] candidates = dir.list(filter);
048        if (candidates == null) {
049          return;
050        }
051        for (int i = 0; i < candidates.length; i++) {
052          File tmp = new File(dir + FILE_SEP + candidates[i]);
053          if (tmp.isDirectory()) {
054            if (recurse) {
055              scanDirectory(tmp, list, true);
056            }
057          } else {
058            list.add(new File(dir + FILE_SEP + candidates[i]));
059          }
060        }
061      }
062    }