Utilities - Data Structures and Problem Solving Using Java - page 491

1 import java.io.IOException;
2 import java.io.OutputStream;
3 import java.io.DataOutputStream;
4 import java.io.ByteArrayInputStream;
5 import java.io.ByteArrayOutputStream;
6
7 /**
8 * Writes to HZIPOutputStream are compressed and
9 * sent to the output stream being wrapped.
10 * No writing is actually done until close.
11 */
12 public class HZIPOutputStream extends OutputStream
13 {
14 public HZIPOutputStream( OutputStream out ) throws IOException
15 {
16 dout = new DataOutputStream( out );
17 }
18
19 public void write( int ch ) throws IOException
20 {
21 byteOut.write( ch );
22 }
23
24 public void close( ) throws IOException
25 {
26 byte [ ] theInput = byteOut.toByteArray( );
27 ByteArrayInputStream byteIn = new ByteArrayInputStream( theInput );
28
29 CharCounter countObj = new CharCounter( byteIn );
30 byteIn.close( );
31
32 HuffmanTree codeTree = new HuffmanTree( countObj );
33 codeTree.writeEncodingTable( dout );
34
35 BitOutputStream bout = new BitOutputStream( dout );
36
37 for( int i = 0; i < theInput.length; i++ )
38 bout.writeBits( codeTree.getCode( theInput[ i ] & 0xff ) );
39 bout.writeBits( codeTree.getCode( BitUtils.EOF ) );
40
41 bout.close( );
42 byteOut.close( );
43 }
44
45 private ByteArrayOutputStream byteOut = new ByteArrayOutputStream( );
46 private DataOutputStream dout;
47 }
figure 12.23
The HZIPOutputStream class