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    package org.apache.commons.compress.compressors.bzip2;
020    
021    import java.util.LinkedHashMap;
022    import java.util.Map;
023    import org.apache.commons.compress.compressors.FileNameUtil;
024    
025    /**
026     * Utility code for the BZip2 compression format.
027     * @ThreadSafe
028     * @since Commons Compress 1.1
029     */
030    public abstract class BZip2Utils {
031    
032        private static final FileNameUtil fileNameUtil;
033    
034        static {
035            Map<String, String> uncompressSuffix =
036                new LinkedHashMap<String, String>();
037            // backwards compatibilty: BZip2Utils never created the short
038            // tbz form, so .tar.bz2 has to be added explicitly
039            uncompressSuffix.put(".tar.bz2", ".tar");
040            uncompressSuffix.put(".tbz2", ".tar");
041            uncompressSuffix.put(".tbz", ".tar");
042            uncompressSuffix.put(".bz2", "");
043            uncompressSuffix.put(".bz", "");
044            fileNameUtil = new FileNameUtil(uncompressSuffix, ".bz2");
045        }
046    
047        /** Private constructor to prevent instantiation of this utility class. */
048        private BZip2Utils() {
049        }
050    
051        /**
052         * Detects common bzip2 suffixes in the given filename.
053         *
054         * @param filename name of a file
055         * @return {@code true} if the filename has a common bzip2 suffix,
056         *         {@code false} otherwise
057         */
058        public static boolean isCompressedFilename(String filename) {
059            return fileNameUtil.isCompressedFilename(filename);
060        }
061    
062        /**
063         * Maps the given name of a bzip2-compressed file to the name that the
064         * file should have after uncompression. Commonly used file type specific
065         * suffixes like ".tbz" or ".tbz2" are automatically detected and
066         * correctly mapped. For example the name "package.tbz2" is mapped to
067         * "package.tar". And any filenames with the generic ".bz2" suffix
068         * (or any other generic bzip2 suffix) is mapped to a name without that
069         * suffix. If no bzip2 suffix is detected, then the filename is returned
070         * unmapped.
071         *
072         * @param filename name of a file
073         * @return name of the corresponding uncompressed file
074         */
075        public static String getUncompressedFilename(String filename) {
076            return fileNameUtil.getUncompressedFilename(filename);
077        }
078    
079        /**
080         * Maps the given filename to the name that the file should have after
081         * compression with bzip2. Currently this method simply appends the suffix
082         * ".bz2" to the filename based on the standard behaviour of the "bzip2"
083         * program, but a future version may implement a more complex mapping if
084         * a new widely used naming pattern emerges.
085         *
086         * @param filename name of a file
087         * @return name of the corresponding compressed file
088         */
089        public static String getCompressedFilename(String filename) {
090            return fileNameUtil.getCompressedFilename(filename);
091        }
092    
093    }