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 020package org.apache.commons.compress.compressors.pack200; 021 022import java.io.File; 023import java.io.FilterInputStream; 024import java.io.IOException; 025import java.io.InputStream; 026import java.util.Map; 027import java.util.jar.JarOutputStream; 028import java.util.jar.Pack200; 029 030import org.apache.commons.compress.compressors.CompressorInputStream; 031 032/** 033 * An input stream that decompresses from the Pack200 format to be read 034 * as any other stream. 035 * 036 * <p>The {@link CompressorInputStream#getCount getCount} and {@link 037 * CompressorInputStream#getBytesRead getBytesRead} methods always 038 * return 0.</p> 039 * 040 * @NotThreadSafe 041 * @since 1.3 042 */ 043public class Pack200CompressorInputStream extends CompressorInputStream { 044 private final InputStream originalInput; 045 private final StreamBridge streamBridge; 046 047 /** 048 * Decompresses the given stream, caching the decompressed data in 049 * memory. 050 * 051 * <p>When reading from a file the File-arg constructor may 052 * provide better performance.</p> 053 * 054 * @param in the InputStream from which this object should be created 055 * @throws IOException if reading fails 056 */ 057 public Pack200CompressorInputStream(final InputStream in) 058 throws IOException { 059 this(in, Pack200Strategy.IN_MEMORY); 060 } 061 062 /** 063 * Decompresses the given stream using the given strategy to cache 064 * the results. 065 * 066 * <p>When reading from a file the File-arg constructor may 067 * provide better performance.</p> 068 * 069 * @param in the InputStream from which this object should be created 070 * @param mode the strategy to use 071 * @throws IOException if reading fails 072 */ 073 public Pack200CompressorInputStream(final InputStream in, 074 final Pack200Strategy mode) 075 throws IOException { 076 this(in, null, mode, null); 077 } 078 079 /** 080 * Decompresses the given stream, caching the decompressed data in 081 * memory and using the given properties. 082 * 083 * <p>When reading from a file the File-arg constructor may 084 * provide better performance.</p> 085 * 086 * @param in the InputStream from which this object should be created 087 * @param props Pack200 properties to use 088 * @throws IOException if reading fails 089 */ 090 public Pack200CompressorInputStream(final InputStream in, 091 final Map<String, String> props) 092 throws IOException { 093 this(in, Pack200Strategy.IN_MEMORY, props); 094 } 095 096 /** 097 * Decompresses the given stream using the given strategy to cache 098 * the results and the given properties. 099 * 100 * <p>When reading from a file the File-arg constructor may 101 * provide better performance.</p> 102 * 103 * @param in the InputStream from which this object should be created 104 * @param mode the strategy to use 105 * @param props Pack200 properties to use 106 * @throws IOException if reading fails 107 */ 108 public Pack200CompressorInputStream(final InputStream in, 109 final Pack200Strategy mode, 110 final Map<String, String> props) 111 throws IOException { 112 this(in, null, mode, props); 113 } 114 115 /** 116 * Decompresses the given file, caching the decompressed data in 117 * memory. 118 * 119 * @param f the file to decompress 120 * @throws IOException if reading fails 121 */ 122 public Pack200CompressorInputStream(final File f) throws IOException { 123 this(f, Pack200Strategy.IN_MEMORY); 124 } 125 126 /** 127 * Decompresses the given file using the given strategy to cache 128 * the results. 129 * 130 * @param f the file to decompress 131 * @param mode the strategy to use 132 * @throws IOException if reading fails 133 */ 134 public Pack200CompressorInputStream(final File f, final Pack200Strategy mode) 135 throws IOException { 136 this(null, f, mode, null); 137 } 138 139 /** 140 * Decompresses the given file, caching the decompressed data in 141 * memory and using the given properties. 142 * 143 * @param f the file to decompress 144 * @param props Pack200 properties to use 145 * @throws IOException if reading fails 146 */ 147 public Pack200CompressorInputStream(final File f, 148 final Map<String, String> props) 149 throws IOException { 150 this(f, Pack200Strategy.IN_MEMORY, props); 151 } 152 153 /** 154 * Decompresses the given file using the given strategy to cache 155 * the results and the given properties. 156 * 157 * @param f the file to decompress 158 * @param mode the strategy to use 159 * @param props Pack200 properties to use 160 * @throws IOException if reading fails 161 */ 162 public Pack200CompressorInputStream(final File f, final Pack200Strategy mode, 163 final Map<String, String> props) 164 throws IOException { 165 this(null, f, mode, props); 166 } 167 168 private Pack200CompressorInputStream(final InputStream in, final File f, 169 final Pack200Strategy mode, 170 final Map<String, String> props) 171 throws IOException { 172 originalInput = in; 173 streamBridge = mode.newStreamBridge(); 174 final JarOutputStream jarOut = new JarOutputStream(streamBridge); 175 final Pack200.Unpacker u = Pack200.newUnpacker(); 176 if (props != null) { 177 u.properties().putAll(props); 178 } 179 if (f == null) { 180 u.unpack(new FilterInputStream(in) { 181 @Override 182 public void close() { 183 // unpack would close this stream but we 184 // want to give the user code more control 185 } 186 }, 187 jarOut); 188 } else { 189 u.unpack(f, jarOut); 190 } 191 jarOut.close(); 192 } 193 194 @Override 195 public int read() throws IOException { 196 return streamBridge.getInput().read(); 197 } 198 199 @Override 200 public int read(final byte[] b) throws IOException { 201 return streamBridge.getInput().read(b); 202 } 203 204 @Override 205 public int read(final byte[] b, final int off, final int count) throws IOException { 206 return streamBridge.getInput().read(b, off, count); 207 } 208 209 @Override 210 public int available() throws IOException { 211 return streamBridge.getInput().available(); 212 } 213 214 @Override 215 public boolean markSupported() { 216 try { 217 return streamBridge.getInput().markSupported(); 218 } catch (final IOException ex) { 219 return false; 220 } 221 } 222 223 @Override 224 public void mark(final int limit) { 225 try { 226 streamBridge.getInput().mark(limit); 227 } catch (final IOException ex) { 228 throw new RuntimeException(ex); 229 } 230 } 231 232 @Override 233 public void reset() throws IOException { 234 streamBridge.getInput().reset(); 235 } 236 237 @Override 238 public long skip(final long count) throws IOException { 239 return streamBridge.getInput().skip(count); 240 } 241 242 @Override 243 public void close() throws IOException { 244 try { 245 streamBridge.stop(); 246 } finally { 247 if (originalInput != null) { 248 originalInput.close(); 249 } 250 } 251 } 252 253 private static final byte[] CAFE_DOOD = new byte[] { 254 (byte) 0xCA, (byte) 0xFE, (byte) 0xD0, (byte) 0x0D 255 }; 256 private static final int SIG_LENGTH = CAFE_DOOD.length; 257 258 /** 259 * Checks if the signature matches what is expected for a pack200 260 * file (0xCAFED00D). 261 * 262 * @param signature 263 * the bytes to check 264 * @param length 265 * the number of bytes to check 266 * @return true, if this stream is a pack200 compressed stream, 267 * false otherwise 268 */ 269 public static boolean matches(final byte[] signature, final int length) { 270 if (length < SIG_LENGTH) { 271 return false; 272 } 273 274 for (int i = 0; i < SIG_LENGTH; i++) { 275 if (signature[i] != CAFE_DOOD[i]) { 276 return false; 277 } 278 } 279 280 return true; 281 } 282}