public synchronized void close() throws IOException {
  writable=false;
  if (map != null) {
    ByteArrayUtil.unmapByteBuffer(map);
    map=null;
  }
  if (lock != null) {
    lock.release();
    lock=null;
  }
  file.close();
}

public synchronized void close ( ) throws IOException { writable = false ; if ( map != null ) { ByteArrayUtil . unmapByteBuffer ( map ) ; map = null ; } if ( lock != null ) { lock . release ( ) ; lock = null ; } file . close ( ) ; }
explicitly close the file . note : following operations will likely cause ioexceptions .
