001 /* DeflaterOutputStream.java - Output filter for compressing. 002 Copyright (C) 1999, 2000, 2001, 2004, 2005 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package java.util.zip; 040 041 import java.io.FilterOutputStream; 042 import java.io.IOException; 043 import java.io.OutputStream; 044 045 /* Written using on-line Java Platform 1.2 API Specification 046 * and JCL book. 047 * Believed complete and correct. 048 */ 049 050 /** 051 * This is a special FilterOutputStream deflating the bytes that are 052 * written through it. It uses the Deflater for deflating. 053 * 054 * A special thing to be noted is that flush() doesn't flush 055 * everything in Sun's JDK, but it does so in jazzlib. This is because 056 * Sun's Deflater doesn't have a way to flush() everything, without 057 * finishing the stream. 058 * 059 * @author Tom Tromey, Jochen Hoenicke 060 * @date Jan 11, 2001 061 */ 062 public class DeflaterOutputStream extends FilterOutputStream 063 { 064 /** 065 * This buffer is used temporarily to retrieve the bytes from the 066 * deflater and write them to the underlying output stream. 067 */ 068 protected byte[] buf; 069 070 /** 071 * The deflater which is used to deflate the stream. 072 */ 073 protected Deflater def; 074 075 /** 076 * Deflates everything in the def's input buffers. This will call 077 * <code>def.deflate()</code> until all bytes from the input buffers 078 * are processed. 079 */ 080 protected void deflate() throws IOException 081 { 082 while (! def.needsInput()) 083 { 084 int len = def.deflate(buf, 0, buf.length); 085 086 // System.err.println("DOS deflated " + len + " out of " + buf.length); 087 if (len <= 0) 088 break; 089 out.write(buf, 0, len); 090 } 091 092 if (! def.needsInput()) 093 throw new InternalError("Can't deflate all input?"); 094 } 095 096 /** 097 * Creates a new DeflaterOutputStream with a default Deflater and 098 * default buffer size. 099 * @param out the output stream where deflated output should be written. 100 */ 101 public DeflaterOutputStream(OutputStream out) 102 { 103 this(out, new Deflater(), 4096); 104 } 105 106 /** 107 * Creates a new DeflaterOutputStream with the given Deflater and 108 * default buffer size. 109 * @param out the output stream where deflated output should be written. 110 * @param defl the underlying deflater. 111 */ 112 public DeflaterOutputStream(OutputStream out, Deflater defl) 113 { 114 this(out, defl, 4096); 115 } 116 117 /** 118 * Creates a new DeflaterOutputStream with the given Deflater and 119 * buffer size. 120 * @param out the output stream where deflated output should be written. 121 * @param defl the underlying deflater. 122 * @param bufsize the buffer size. 123 * @exception IllegalArgumentException if bufsize isn't positive. 124 */ 125 public DeflaterOutputStream(OutputStream out, Deflater defl, int bufsize) 126 { 127 super(out); 128 if (bufsize <= 0) 129 throw new IllegalArgumentException("bufsize <= 0"); 130 buf = new byte[bufsize]; 131 def = defl; 132 } 133 134 /** 135 * Flushes the stream by calling flush() on the deflater and then 136 * on the underlying stream. This ensures that all bytes are 137 * flushed. This function doesn't work in Sun's JDK, but only in 138 * jazzlib. 139 */ 140 public void flush() throws IOException 141 { 142 def.flush(); 143 deflate(); 144 out.flush(); 145 } 146 147 /** 148 * Finishes the stream by calling finish() on the deflater. This 149 * was the only way to ensure that all bytes are flushed in Sun's 150 * JDK. 151 */ 152 public void finish() throws IOException 153 { 154 def.finish(); 155 while (! def.finished()) 156 { 157 int len = def.deflate(buf, 0, buf.length); 158 if (len <= 0) 159 break; 160 out.write(buf, 0, len); 161 } 162 if (! def.finished()) 163 throw new InternalError("Can't deflate all input?"); 164 out.flush(); 165 } 166 167 /** 168 * Calls finish() and closes the stream. 169 */ 170 public void close() throws IOException 171 { 172 finish(); 173 out.close(); 174 } 175 176 /** 177 * Writes a single byte to the compressed output stream. 178 * @param bval the byte value. 179 */ 180 public void write(int bval) throws IOException 181 { 182 byte[] b = new byte[1]; 183 b[0] = (byte) bval; 184 write(b, 0, 1); 185 } 186 187 /** 188 * Writes a len bytes from an array to the compressed stream. 189 * @param buf the byte array. 190 * @param off the offset into the byte array where to start. 191 * @param len the number of bytes to write. 192 */ 193 public void write(byte[] buf, int off, int len) throws IOException 194 { 195 def.setInput(buf, off, len); 196 deflate(); 197 } 198 }