public JBZipOutputStream(JBZipFile file,long currentCDOffset) throws IOException {
  myFile=file;
  raf=myFile.archive;
  written=currentCDOffset;
  raf.seek(currentCDOffset);
}

public JBZipOutputStream ( JBZipFile file , long currentCDOffset ) throws IOException { myFile = file ; raf = myFile . archive ; written = currentCDOffset ; raf . seek ( currentCDOffset ) ; }
creates a new zip outputstream writing to a file . will use random access if possible .
