Java tutorial
//package com.java2s; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ import java.util.HashMap; import java.util.Locale; import java.util.Map; public class Main { /** * Map from common filename suffixes of bzip2ed files to the corresponding * suffixes of uncompressed files. For example: from ".tbz2" to ".tar". * <p> * This map also contains bzip2-specific suffixes like ".bz2". These * suffixes are mapped to the empty string, as they should simply be * removed from the filename when the file is uncompressed. */ private static final Map uncompressSuffix = new HashMap(); /** * Maps the given name of a bzip2-compressed file to the name that the * file should have after uncompression. Commonly used file type specific * suffixes like ".tbz" or ".tbz2" are automatically detected and * correctly mapped. For example the name "package.tbz2" is mapped to * "package.tar". And any filenames with the generic ".bz2" suffix * (or any other generic bzip2 suffix) is mapped to a name without that * suffix. If no bzip2 suffix is detected, then the filename is returned * unmapped. * * @param filename name of a file * @return name of the corresponding uncompressed file */ public static String getUncompressedFilename(String filename) { String lower = filename.toLowerCase(Locale.ENGLISH); int n = lower.length(); // Shortest suffix is three letters (.bz), longest is five (.tbz2) for (int i = 3; i <= 5 && i < n; i++) { Object suffix = uncompressSuffix.get(lower.substring(n - i)); if (suffix != null) { return filename.substring(0, n - i) + suffix; } } return filename; } }