1 /* InflaterInputStream.java - Input stream filter for decompressing 2 Copyright (C) 1999, 2000, 2002, 2003 Free Software Foundation, Inc. 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 package java.util.zip; 39 40 import java.io.FilterInputStream; 41 import java.io.InputStream; 42 import java.io.IOException; 43 44 /** 45 * @author Tom Tromey 46 * @date May 17, 1999 47 */ 48 49 /* Written using on-line Java Platform 1.2 API Specification 50 * and JCL book. 51 * Believed complete and correct. 52 */ 53 54 public class InflaterInputStream extends FilterInputStream 55 { fill()56 protected void fill () throws IOException 57 { 58 len = in.read(buf, 0, buf.length); 59 if (len != -1) 60 inf.setInput(buf, 0, len); 61 } 62 InflaterInputStream(InputStream in)63 public InflaterInputStream (InputStream in) 64 { 65 this (in, new Inflater (), 512); 66 } 67 InflaterInputStream(InputStream in, Inflater infl)68 public InflaterInputStream (InputStream in, Inflater infl) 69 { 70 this (in, infl, 512); 71 } 72 InflaterInputStream(InputStream in, Inflater inf, int size)73 public InflaterInputStream (InputStream in, Inflater inf, int size) 74 { 75 super (in); 76 77 if (in == null) 78 throw new NullPointerException ("in may not be null"); 79 80 if (inf == null) 81 throw new NullPointerException ("inf may not be null"); 82 83 if (size < 0) 84 throw new IllegalArgumentException ("size may not be negative"); 85 86 this.inf = inf; 87 this.buf = new byte [size]; 88 } 89 read()90 public int read () throws IOException 91 { 92 byte[] buf = new byte[1]; 93 int r = read (buf, 0, 1); 94 if (r != -1) 95 r = buf[0] & 0xff; 96 return r; 97 } 98 read(byte[] buf, int off, int len)99 public int read (byte[] buf, int off, int len) throws IOException 100 { 101 if (inf == null) 102 throw new IOException ("stream closed"); 103 if (len == 0) 104 return 0; 105 if (inf.finished()) 106 return -1; 107 108 int count = 0; 109 while (count == 0) 110 { 111 if (inf.needsInput()) 112 fill (); 113 try 114 { 115 count = inf.inflate(buf, off, len); 116 if (count == 0) 117 { 118 if (this.len == -1) 119 { 120 // Couldn't get any more data to feed to the Inflater 121 return -1; 122 } 123 if (inf.needsDictionary()) 124 throw new ZipException ("Inflater needs Dictionary"); 125 } 126 } 127 catch (DataFormatException dfe) 128 { 129 throw new ZipException (dfe.getMessage()); 130 } 131 } 132 return count; 133 } 134 close()135 public void close () throws IOException 136 { 137 inf = null; 138 super.close (); 139 } 140 available()141 public int available () throws IOException 142 { 143 // According to the JDK 1.2 docs, this should only ever return 0 144 // or 1 and should not be relied upon by Java programs. 145 if (inf == null) 146 throw new IOException ("stream closed"); 147 return inf.finished () ? 0 : 1; 148 } 149 skip(long n)150 public long skip (long n) throws IOException 151 { 152 if (inf == null) 153 throw new IOException ("stream closed"); 154 155 if (n == 0) 156 return 0; 157 158 int min = (int) Math.min(n, 1024); 159 byte[] buf = new byte[min]; 160 161 long s = 0; 162 while (n > 0) 163 { 164 int r = read (buf, 0, min); 165 if (r == -1) 166 break; 167 n -= r; 168 s += r; 169 min = (int) Math.min(n, 1024); 170 } 171 172 return s; 173 } 174 175 // Buffer for delivering uncompressed data to inflater. 176 protected byte[] buf; 177 178 // Inflater used to decompress data. 179 protected Inflater inf; 180 181 // Number of read bytes in buf. 182 protected int len; 183 } 184