Using GZIP streams to compress

First time poster, long time reader

I'm trying to write some serializable objects (ArrayLists) to file, but I wanted to compress them first. The GZIP stream isn't doing anything, even when it should. How should I be using it? Thanks if you can help

public void save( String filename )

{

try {

File file = new File( filename );

FileOutputStream outStream = new FileOutputStream( file );

GZIPOutputStream zipOut = new GZIPOutputStream( outStream );

ObjectOutputStream out = new ObjectOutputStream( zipOut );

out.writeObject( xList );

out.writeObject( yList );

out.writeObject( list );

out.close();

} catch (IOException e) {

System.exit( 1 );

}

}

[748 byte] By [avdokreissa] at [2007-10-2 15:59:38]