001    /****************************************************************
002     * Licensed to the Apache Software Foundation (ASF) under one   *
003     * or more contributor license agreements.  See the NOTICE file *
004     * distributed with this work for additional information        *
005     * regarding copyright ownership.  The ASF licenses this file   *
006     * to you under the Apache License, Version 2.0 (the            *
007     * "License"); you may not use this file except in compliance   *
008     * with the License.  You may obtain a copy of the License at   *
009     *                                                              *
010     *   http://www.apache.org/licenses/LICENSE-2.0                 *
011     *                                                              *
012     * Unless required by applicable law or agreed to in writing,   *
013     * software distributed under the License is distributed on an  *
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
015     * KIND, either express or implied.  See the License for the    *
016     * specific language governing permissions and limitations      *
017     * under the License.                                           *
018     ****************************************************************/
019    
020    package org.apache.james.repository.file;
021    
022    import java.io.File;
023    import java.io.FilenameFilter;
024    
025    /**
026     * This filters files based on the extension and is tailored to provide
027     * backwards compatibility of the numbered repositories that Avalon does.
028     */
029    public class NumberedRepositoryFileFilter implements FilenameFilter {
030        private String postfix;
031        private String prefix;
032    
033        /**
034         * Default Constructor
035         * 
036         * @param extension
037         *            the extension for which checked
038         */
039        public NumberedRepositoryFileFilter(final String extension) {
040            postfix = extension;
041            prefix = ".Repository";
042        }
043    
044        /**
045         * @see java.io.FilenameFilter#accept(File, String)
046         */
047        public boolean accept(final File file, final String name) {
048            // System.out.println("check: " + name);
049            // System.out.println("post: " + postfix);
050            if (!name.endsWith(postfix)) {
051                return false;
052            }
053            // Look for a couple of digits next
054            int pos = name.length() - postfix.length();
055            // We have to find at least one digit... if not then this isn't what we
056            // want
057            if (!Character.isDigit(name.charAt(pos - 1))) {
058                return false;
059            }
060            pos--;
061            while (pos >= 1 && Character.isDigit(name.charAt(pos - 1))) {
062                // System.out.println("back one");
063                pos--;
064            }
065            // System.out.println("sub: " + name.substring(0, pos));
066            // Now want to check that we match the rest
067            return name.substring(0, pos).endsWith(prefix);
068        }
069    }