public static byte[] long2buff(long n){
  byte[] bs;
  bs=new byte[8];
  bs[0]=(byte)((n >> 56) & 0xFF);
  bs[1]=(byte)((n >> 48) & 0xFF);
  bs[2]=(byte)((n >> 40) & 0xFF);
  bs[3]=(byte)((n >> 32) & 0xFF);
  bs[4]=(byte)((n >> 24) & 0xFF);
  bs[5]=(byte)((n >> 16) & 0xFF);
  bs[6]=(byte)((n >> 8) & 0xFF);
  bs[7]=(byte)(n & 0xFF);
  return bs;
}

public static byte [ ] long2buff ( long n ) { byte [ ] bs ; bs = new byte [ 8 ] ; bs [ 0 ] = ( byte ) ( ( n > > 56 ) & 0xFF ) ; bs [ 1 ] = ( byte ) ( ( n > > 48 ) & 0xFF ) ; bs [ 2 ] = ( byte ) ( ( n > > 40 ) & 0xFF ) ; bs [ 3 ] = ( byte ) ( ( n > > 32 ) & 0xFF ) ; bs [ 4 ] = ( byte ) ( ( n > > 24 ) & 0xFF ) ; bs [ 5 ] = ( byte ) ( ( n > > 16 ) & 0xFF ) ; bs [ 6 ] = ( byte ) ( ( n > > 8 ) & 0xFF ) ; bs [ 7 ] = ( byte ) ( n & 0xFF ) ; return bs ; }
long convert to buff ( big - endian )
