001    /*
002     * Copyright (c) 2005 Einar Pehrson <einar@pehrson.nu>.
003     *
004     * This file is part of
005     * CleanSheets - a spreadsheet application for the Java platform.
006     *
007     * CleanSheets is free software; you can redistribute it and/or modify
008     * it under the terms of the GNU General Public License as published by
009     * the Free Software Foundation; either version 2 of the License, or
010     * (at your option) any later version.
011     *
012     * CleanSheets is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
015     * GNU General Public License for more details.
016     *
017     * You should have received a copy of the GNU General Public License
018     * along with CleanSheets; if not, write to the Free Software
019     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
020     */
021    package csheets.io;
022    
023    import java.io.File;
024    import java.io.FilenameFilter;
025    import java.util.Arrays;
026    import java.util.List;
027    
028    /**
029     * A filename filter for filtering on filename extensions.
030     * @author Einar Pehrson
031     */
032    public class FilenameExtensionFilter implements FilenameFilter {
033    
034            /** The extensions of allowed files. */
035            private List<String> extensions;
036    
037            /**
038             * Creates a new filter for files with the given extensions.
039             * @param extensions the extension of allowed files
040             */
041            public FilenameExtensionFilter(String... extensions) {
042                    this(Arrays.asList(extensions));
043            }
044    
045            /**
046             * Creates a new filter for files with the given extensions.
047             * @param extensions the extension of allowed files
048             */
049            public FilenameExtensionFilter(List<String> extensions) {
050                    if (extensions.size() == 0)
051                            throw new IllegalArgumentException();
052                    this.extensions = extensions;
053            }
054    
055            public boolean accept(File file, String filename) {
056                    String extension = filename.substring(filename.lastIndexOf('.') + 1).toLowerCase().trim();
057                    return extensions.contains(extension);
058            }
059    
060            /**
061             * Returns the file extensions that the filter allows.
062             * @return the file extensions that the filter allows
063             */
064            public String[] getExtensions() {
065                    return extensions.toArray(new String[extensions.size()]);
066            }
067    }