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 }