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 */ 019 package org.apache.commons.compress.compressors; 020 021 import java.io.IOException; 022 import java.io.InputStream; 023 import java.io.OutputStream; 024 025 import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream; 026 import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream; 027 import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream; 028 import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream; 029 import org.apache.commons.compress.compressors.pack200.Pack200CompressorInputStream; 030 import org.apache.commons.compress.compressors.pack200.Pack200CompressorOutputStream; 031 032 /** 033 * <p>Factory to create Compressor[In|Out]putStreams from names. To add other 034 * implementations you should extend CompressorStreamFactory and override the 035 * appropriate methods (and call their implementation from super of course).</p> 036 * 037 * Example (Compressing a file): 038 * 039 * <pre> 040 * final OutputStream out = new FileOutputStream(output); 041 * CompressorOutputStream cos = 042 * new CompressorStreamFactory().createCompressorOutputStream(CompressorStreamFactory.BZIP2, out); 043 * IOUtils.copy(new FileInputStream(input), cos); 044 * cos.close(); 045 * </pre> 046 * 047 * Example (Compressing a file): 048 * <pre> 049 * final InputStream is = new FileInputStream(input); 050 * CompressorInputStream in = 051 * new CompressorStreamFactory().createCompressorInputStream(CompressorStreamFactory.BZIP2, is); 052 * IOUtils.copy(in, new FileOutputStream(output)); 053 * in.close(); 054 * </pre> 055 * 056 * @Immutable 057 */ 058 public class CompressorStreamFactory { 059 060 /** 061 * Constant used to identify the BZIP2 compression algorithm. 062 * @since Commons Compress 1.1 063 */ 064 public static final String BZIP2 = "bzip2"; 065 /** 066 * Constant used to identify the GZIP compression algorithm. 067 * @since Commons Compress 1.1 068 */ 069 public static final String GZIP = "gz"; 070 /** 071 * Constant used to identify the PACK200 compression algorithm. 072 * @since Commons Compress 1.3 073 */ 074 public static final String PACK200 = "pack200"; 075 076 /** 077 * Create an compressor input stream from an input stream, autodetecting 078 * the compressor type from the first few bytes of the stream. The InputStream 079 * must support marks, like BufferedInputStream. 080 * 081 * @param in the input stream 082 * @return the compressor input stream 083 * @throws CompressorException if the compressor name is not known 084 * @throws IllegalArgumentException if the stream is null or does not support mark 085 * @since Commons Compress 1.1 086 */ 087 public CompressorInputStream createCompressorInputStream(final InputStream in) 088 throws CompressorException { 089 if (in == null) { 090 throw new IllegalArgumentException("Stream must not be null."); 091 } 092 093 if (!in.markSupported()) { 094 throw new IllegalArgumentException("Mark is not supported."); 095 } 096 097 final byte[] signature = new byte[12]; 098 in.mark(signature.length); 099 try { 100 int signatureLength = in.read(signature); 101 in.reset(); 102 103 if (BZip2CompressorInputStream.matches(signature, signatureLength)) { 104 return new BZip2CompressorInputStream(in); 105 } 106 107 if (GzipCompressorInputStream.matches(signature, signatureLength)) { 108 return new GzipCompressorInputStream(in); 109 } 110 111 if (Pack200CompressorInputStream.matches(signature, signatureLength)) { 112 return new Pack200CompressorInputStream(in); 113 } 114 115 } catch (IOException e) { 116 throw new CompressorException("Failed to detect Compressor from InputStream.", e); 117 } 118 119 throw new CompressorException("No Compressor found for the stream signature."); 120 } 121 122 /** 123 * Create a compressor input stream from a compressor name and an input stream. 124 * 125 * @param name of the compressor, i.e. "gz", "bzip2" or "pack200" 126 * @param in the input stream 127 * @return compressor input stream 128 * @throws CompressorException if the compressor name is not known 129 * @throws IllegalArgumentException if the name or input stream is null 130 */ 131 public CompressorInputStream createCompressorInputStream(final String name, 132 final InputStream in) throws CompressorException { 133 if (name == null || in == null) { 134 throw new IllegalArgumentException( 135 "Compressor name and stream must not be null."); 136 } 137 138 try { 139 140 if (GZIP.equalsIgnoreCase(name)) { 141 return new GzipCompressorInputStream(in); 142 } 143 144 if (BZIP2.equalsIgnoreCase(name)) { 145 return new BZip2CompressorInputStream(in); 146 } 147 148 if (PACK200.equalsIgnoreCase(name)) { 149 return new Pack200CompressorInputStream(in); 150 } 151 152 } catch (IOException e) { 153 throw new CompressorException( 154 "Could not create CompressorInputStream.", e); 155 } 156 throw new CompressorException("Compressor: " + name + " not found."); 157 } 158 159 /** 160 * Create an compressor output stream from an compressor name and an input stream. 161 * 162 * @param name the compressor name, i.e. "gz", "bzip2" or "pack200" 163 * @param out the output stream 164 * @return the compressor output stream 165 * @throws CompressorException if the archiver name is not known 166 * @throws IllegalArgumentException if the archiver name or stream is null 167 */ 168 public CompressorOutputStream createCompressorOutputStream( 169 final String name, final OutputStream out) 170 throws CompressorException { 171 if (name == null || out == null) { 172 throw new IllegalArgumentException( 173 "Compressor name and stream must not be null."); 174 } 175 176 try { 177 178 if (GZIP.equalsIgnoreCase(name)) { 179 return new GzipCompressorOutputStream(out); 180 } 181 182 if (BZIP2.equalsIgnoreCase(name)) { 183 return new BZip2CompressorOutputStream(out); 184 } 185 186 if (PACK200.equalsIgnoreCase(name)) { 187 return new Pack200CompressorOutputStream(out); 188 } 189 190 } catch (IOException e) { 191 throw new CompressorException( 192 "Could not create CompressorOutputStream", e); 193 } 194 throw new CompressorException("Compressor: " + name + " not found."); 195 } 196 }