public synchronized void write(byte[] buf,int off,int len) throws IOException {
  super.write(buf,off,len);
  crc.update(buf,off,len);
}

public synchronized void write ( byte [ ] buf , int off , int len ) throws IOException { super . write ( buf , off , len ) ; crc . update ( buf , off , len ) ; }
writes array of bytes to the compressed output stream . this method will block until all the bytes are written .
