    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    /**
    049     * Maps the given file name to the name that the file should have after
    050     * compression with bzip2. Currently this method simply appends the suffix
    051     * ".bz2" to the file name based on the standard behavior of the "bzip2"
    052     * program, but a future version may implement a more complex mapping if
    053     * a new widely used naming pattern emerges.
    054     *
    055     * @param fileName name of a file
    056     * @return name of the corresponding compressed file
    057     */
    058    public static String getCompressedFilename(final String fileName) {
    059        return fileNameUtil.getCompressedFilename(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 file names 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 file name 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(final String fileName) {
    076        return fileNameUtil.getUncompressedFilename(fileName);
    077    }
    078
    079    /**
    080     * Detects common bzip2 suffixes in the given file name.
    081     *
    082     * @param fileName name of a file
    083     * @return {@code true} if the file name has a common bzip2 suffix,
    084     *         {@code false} otherwise
    085     */
    086    public static boolean isCompressedFilename(final String fileName) {
    087        return fileNameUtil.isCompressedFilename(fileName);
    088    }
    089
    090    /** Private constructor to prevent instantiation of this utility class. */
    091    private BZip2Utils() {
    092    }
    093
    094}