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 */
019package org.apache.commons.compress.compressors.bzip2;
020
021import java.util.LinkedHashMap;
022import java.util.Map;
023
024import org.apache.commons.compress.compressors.FileNameUtil;
025
026/**
027 * Utility code for the BZip2 compression format.
028 * @ThreadSafe
029 * @since 1.1
030 */
031public abstract class BZip2Utils {
032
033    private static final FileNameUtil fileNameUtil;
034
035    static {
036        final Map<String, String> uncompressSuffix =
037            new LinkedHashMap<>();
038        // backwards compatibility: BZip2Utils never created the short
039        // tbz form, so .tar.bz2 has to be added explicitly
040        uncompressSuffix.put(".tar.bz2", ".tar");
041        uncompressSuffix.put(".tbz2", ".tar");
042        uncompressSuffix.put(".tbz", ".tar");
043        uncompressSuffix.put(".bz2", "");
044        uncompressSuffix.put(".bz", "");
045        fileNameUtil = new FileNameUtil(uncompressSuffix, ".bz2");
046    }
047
048    /** Private constructor to prevent instantiation of this utility class. */
049    private BZip2Utils() {
050    }
051
052    /**
053     * Detects common bzip2 suffixes in the given file name.
054     *
055     * @param fileName name of a file
056     * @return {@code true} if the file name has a common bzip2 suffix,
057     *         {@code false} otherwise
058     */
059    public static boolean isCompressedFilename(final String fileName) {
060        return fileNameUtil.isCompressedFilename(fileName);
061    }
062
063    /**
064     * Maps the given name of a bzip2-compressed file to the name that the
065     * file should have after uncompression. Commonly used file type specific
066     * suffixes like ".tbz" or ".tbz2" are automatically detected and
067     * correctly mapped. For example the name "package.tbz2" is mapped to
068     * "package.tar". And any file names with the generic ".bz2" suffix
069     * (or any other generic bzip2 suffix) is mapped to a name without that
070     * suffix. If no bzip2 suffix is detected, then the file name is returned
071     * unmapped.
072     *
073     * @param fileName name of a file
074     * @return name of the corresponding uncompressed file
075     */
076    public static String getUncompressedFilename(final String fileName) {
077        return fileNameUtil.getUncompressedFilename(fileName);
078    }
079
080    /**
081     * Maps the given file name to the name that the file should have after
082     * compression with bzip2. Currently this method simply appends the suffix
083     * ".bz2" to the file name based on the standard behavior of the "bzip2"
084     * program, but a future version may implement a more complex mapping if
085     * a new widely used naming pattern emerges.
086     *
087     * @param fileName name of a file
088     * @return name of the corresponding compressed file
089     */
090    public static String getCompressedFilename(final String fileName) {
091        return fileNameUtil.getCompressedFilename(fileName);
092    }
093
094}