/**************************************************************************
* Copyright (c) 2001 by Punch Telematix. All rights reserved. *
* *
* Redistribution and use in source and binary forms, with or without *
* modification, are permitted provided that the following conditions *
* are met: *
* 1. Redistributions of source code must retain the above copyright *
* notice, this list of conditions and the following disclaimer. *
* 2. Redistributions in binary form must reproduce the above copyright *
* notice, this list of conditions and the following disclaimer in the *
* documentation and/or other materials provided with the distribution. *
* 3. Neither the name of Punch Telematix nor the names of *
* other contributors may be used to endorse or promote products *
* derived from this software without specific prior written permission.*
* *
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED *
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF *
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. *
* IN NO EVENT SHALL PUNCH TELEMATIX OR OTHER CONTRIBUTORS BE LIABLE *
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR *
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF *
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR *
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, *
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE *
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN *
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *
**************************************************************************/
/**
* $Id: GZIPOutputStream.java,v 1.1.1.1 2004/07/12 14:07:47 cvs Exp $
*/
package java.util.zip;
import java.io.OutputStream;
import java.io.IOException;
public class GZIPOutputStream extends DeflaterOutputStream {
protected CRC32 crc = new CRC32();
private static final byte [] GZIPHeader = { 31, -117, 8, 0, 0, 0, 0, 0, 0, 0 };
private boolean finished = false;
public GZIPOutputStream(OutputStream outst) throws IOException {
super(outst, new Deflater(8,true));
out.write(GZIPHeader, 0, GZIPHeader.length);
}
public GZIPOutputStream(OutputStream outst, int readsize) throws IOException {
super(outst, new Deflater(8,true), readsize );
out.write(GZIPHeader, 0, GZIPHeader.length);
}
public void close() throws IOException {
finish();
super.close();
}
public void finish() throws IOException {
if (!finished) {
super.finish();
byte [] trailer = new byte [8];
int i = 0;
int bytes = (int) crc.getValue();
trailer[i++] = (byte)bytes;
bytes = bytes>>>8;
trailer[i++] = (byte)bytes;
bytes = bytes>>>8;
trailer[i++] = (byte)bytes;
bytes = bytes>>>8;
trailer[i++] = (byte)bytes;
bytes = def.getTotalIn();
trailer[i++] = (byte)bytes;
bytes = bytes>>>8;
trailer[i++] = (byte)bytes;
bytes = bytes>>>8;
trailer[i++] = (byte)bytes;
bytes = bytes>>>8;
trailer[i++] = (byte)bytes;
out.write(trailer, 0 , 8);
finished = true;
}
}
public void write(byte [] buf, int offset, int len) throws IOException {
if (finished) {
throw new IOException("stream has finished");
}
crc.update(buf, offset, len); // this method will throw exceptions if needed
super.write(buf, offset, len);
}
}