question: @ Override public final long readLong ( ) throws IOException { d . readFully ( w , 0 , 8 ) ; return ( long ) ( w [ 7 ] ) << 56 | ( long ) ( w [ 6 ] & 0xff ) << 48 | ( long ) ( w [ 5 ] & 0xff ) << 40 | ( long ) ( w [ 4 ] & 0xff ) << 32 | ( long ) ( w [ 3 ] & 0xff ) << 24 | ( long ) ( w [ 2 ] & 0xff ) << 16 | ( long ) ( w [ 1 ] & 0xff ) << 8 | ( long ) ( w [ 0 ] & 0xff ) ; }
target:  like DataInputStream.readLong except little endian.