libjava/java/util/zip/DeflaterOutputStream.java

   1 /* DeflaterOutputStream.java - Output filter for compressing.
   2    Copyright (C) 1999, 2000 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.FilterOutputStream;
  41 import java.io.OutputStream;
  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 DeflaterOutputStream extends FilterOutputStream
  55 {
  56   public void close () throws IOException
  57   {
  58     finish ();
  59     out.close();
  60   }
  61
  62   protected void deflate () throws IOException
  63   {
  64     do
  65       {
  66         int len = def.deflate(buf, 0, buf.length);
  67         if (len > 0)
  68           out.write(buf, 0, len);
  69        }
  70     while (! def.needsInput());
  71   }
  72
  73   public DeflaterOutputStream (OutputStream out)
  74   {
  75     this (out, new Deflater (), 512);
  76   }
  77
  78   public DeflaterOutputStream (OutputStream out, Deflater defl)
  79   {
  80     this (out, defl, 512);
  81   }
  82
  83   public DeflaterOutputStream(OutputStream out, Deflater defl, int bufsize)
  84   {
  85     super (out);
  86     buf = new byte[bufsize];
  87     def = defl;
  88   }
  89
  90   public void finish () throws IOException
  91   {
  92     if (inbufLength > 0)
  93       {
  94         def.setInput (inbuf, 0, inbufLength);
  95         deflate ();
  96         inbufLength = 0;
  97       }
  98     def.finish();
  99     while (! def.finished ())
 100       {
 101         int len = def.deflate(buf, 0, buf.length);
 102         if (len > 0)
 103           out.write(buf, 0, len);
 104       }
 105   }
 106
 107   public void write (int bval) throws IOException
 108   {
 109     if (inbuf == null)
 110       {
 111         inbuf = new byte[128];
 112       }
 113     else if (inbufLength == inbuf.length)
 114       {
 115         def.setInput (inbuf, 0, inbufLength);
 116         deflate ();
 117         inbufLength = 0;
 118       }
 119     inbuf[inbufLength++] = (byte) bval;
 120   }
 121
 122   public void write (byte[] buf, int off, int len) throws IOException
 123   {
 124     if (inbufLength > 0)
 125       {
 126         def.setInput (inbuf, 0, inbufLength);
 127         deflate ();
 128         inbufLength = 0;
 129       }
 130     def.setInput (buf, off, len);
 131     deflate ();
 132   }
 133
 134   // Used, if needed, for write(int).
 135   private byte[] inbuf;
 136   // Used length of inbuf.
 137   private int inbufLength;
 138
 139   // The retrieval buffer.
 140   protected byte[] buf;
 141
 142   // Deflater used to compress data.
 143   protected Deflater def;
 144 }