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(); /** * Detects common bzip2 suffixes in the given filename. * * @param filename name of a file * @return <code>true</code> if the filename has a common bzip2 suffix, * <code>false</code> otherwise */ public static boolean isCompressedFilename(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++) { if (uncompressSuffix.containsKey(lower.substring(n - i))) { return true; } } return false; } }