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.gzip; 020 021import java.nio.charset.Charset; 022import java.nio.charset.StandardCharsets; 023import java.util.LinkedHashMap; 024import java.util.Map; 025 026import org.apache.commons.compress.compressors.FileNameUtil; 027 028/** 029 * Utility code for the gzip compression format. 030 * @ThreadSafe 031 */ 032public class GzipUtils { 033 034 private static final FileNameUtil fileNameUtil; 035 036 static { 037 // using LinkedHashMap so .tgz is preferred over .taz as 038 // compressed extension of .tar as FileNameUtil will use the 039 // first one found 040 final Map<String, String> uncompressSuffix = 041 new LinkedHashMap<>(); 042 uncompressSuffix.put(".tgz", ".tar"); 043 uncompressSuffix.put(".taz", ".tar"); 044 uncompressSuffix.put(".svgz", ".svg"); 045 uncompressSuffix.put(".cpgz", ".cpio"); 046 uncompressSuffix.put(".wmz", ".wmf"); 047 uncompressSuffix.put(".emz", ".emf"); 048 uncompressSuffix.put(".gz", ""); 049 uncompressSuffix.put(".z", ""); 050 uncompressSuffix.put("-gz", ""); 051 uncompressSuffix.put("-z", ""); 052 uncompressSuffix.put("_z", ""); 053 fileNameUtil = new FileNameUtil(uncompressSuffix, ".gz"); 054 } 055 056 /** 057 * Encoding for file name and comments per the <a href="https://tools.ietf.org/html/rfc1952">GZIP File Format Specification</a> 058 */ 059 static final Charset GZIP_ENCODING = StandardCharsets.ISO_8859_1; 060 061 /** 062 * Maps the given file name to the name that the file should have after 063 * compression with gzip. Common file types with custom suffixes for 064 * compressed versions are automatically detected and correctly mapped. 065 * For example the name "package.tar" is mapped to "package.tgz". If no 066 * custom mapping is applicable, then the default ".gz" suffix is appended 067 * to the file name. 068 * 069 * @param fileName name of a file 070 * @return name of the corresponding compressed file 071 * @deprecated Use {@link #getCompressedFileName(String)}. 072 */ 073 @Deprecated 074 public static String getCompressedFilename(final String fileName) { 075 return fileNameUtil.getCompressedFileName(fileName); 076 } 077 078 /** 079 * Maps the given file name to the name that the file should have after 080 * compression with gzip. Common file types with custom suffixes for 081 * compressed versions are automatically detected and correctly mapped. 082 * For example the name "package.tar" is mapped to "package.tgz". If no 083 * custom mapping is applicable, then the default ".gz" suffix is appended 084 * to the file name. 085 * 086 * @param fileName name of a file 087 * @return name of the corresponding compressed file 088 * @since 1.25.0 089 */ 090 public static String getCompressedFileName(final String fileName) { 091 return fileNameUtil.getCompressedFileName(fileName); 092 } 093 094 /** 095 * Maps the given name of a gzip-compressed file to the name that the 096 * file should have after uncompression. Commonly used file type specific 097 * suffixes like ".tgz" or ".svgz" are automatically detected and 098 * correctly mapped. For example the name "package.tgz" is mapped to 099 * "package.tar". And any file names with the generic ".gz" suffix 100 * (or any other generic gzip suffix) is mapped to a name without that 101 * suffix. If no gzip suffix is detected, then the file name is returned 102 * unmapped. 103 * 104 * @param fileName name of a file 105 * @return name of the corresponding uncompressed file 106 * @deprecated Use {@link #getUncompressedFileName(String)}. 107 */ 108 @Deprecated 109 public static String getUncompressedFilename(final String fileName) { 110 return fileNameUtil.getUncompressedFileName(fileName); 111 } 112 113 /** 114 * Maps the given name of a gzip-compressed file to the name that the 115 * file should have after uncompression. Commonly used file type specific 116 * suffixes like ".tgz" or ".svgz" are automatically detected and 117 * correctly mapped. For example the name "package.tgz" is mapped to 118 * "package.tar". And any file names with the generic ".gz" suffix 119 * (or any other generic gzip suffix) is mapped to a name without that 120 * suffix. If no gzip suffix is detected, then the file name is returned 121 * unmapped. 122 * 123 * @param fileName name of a file 124 * @return name of the corresponding uncompressed file 125 * @since 1.25.0 126 */ 127 public static String getUncompressedFileName(final String fileName) { 128 return fileNameUtil.getUncompressedFileName(fileName); 129 } 130 131 /** 132 * Detects common gzip suffixes in the given file name. 133 * 134 * @param fileName name of a file 135 * @return {@code true} if the file name has a common gzip suffix, 136 * {@code false} otherwise 137 * @deprecated Use {@link #isCompressedFileName(String)}. 138 */ 139 @Deprecated 140 public static boolean isCompressedFilename(final String fileName) { 141 return fileNameUtil.isCompressedFileName(fileName); 142 } 143 144 /** 145 * Detects common gzip suffixes in the given file name. 146 * 147 * @param fileName name of a file 148 * @return {@code true} if the file name has a common gzip suffix, 149 * {@code false} otherwise 150 * @since 1.25.0 151 */ 152 public static boolean isCompressedFileName(final String fileName) { 153 return fileNameUtil.isCompressedFileName(fileName); 154 } 155 156 /** Private constructor to prevent instantiation of this utility class. */ 157 private GzipUtils() { 158 } 159 160}