question: private synchronized long flushBuffer ( ) throws IOException { long pos = channel . position ( ) ; int len = ( int ) buffer . getFilePointer ( ) ; byte [ ] bytes = new byte [ len ] ; buffer . writeTo ( bytes , 0 ) ; buffer . reset ( ) ; intBuffer [ 0 ] = ( byte ) ( len > > 24 ) ; intBuffer [ 1 ] = ( byte ) ( len > > 16 ) ; intBuffer [ 2 ] = ( byte ) ( len > > 8 ) ; intBuffer [ 3 ] = ( byte ) len ; intByteBuffer . limit ( 4 ) ; intByteBuffer . position ( 0 ) ; writeBytesToChannel ( intByteBuffer ) ; writeBytesToChannel ( ByteBuffer . wrap ( bytes ) ) ; return pos ; }
target:  Writes buffer to the file and returns the start position. 