question: @ Override public int read ( byte b [ ] , int off , int len ) throws IOException { if ( bb == null ) { throw new IOException ( "read on a closed InputStream" ) ; } if ( b == null ) { throw new NullPointerException ( ) ; } else if ( off < 0 || len < 0 || len > b . length - off ) { throw new IndexOutOfBoundsException ( ) ; } else if ( len == 0 ) { return 0 ; } int length = Math . min ( bb . remaining ( ) , len ) ; if ( length == 0 ) { return - 1 ; } bb . get ( b , off , length ) ; return length ; }
target:  Returns a byte array from the ByteBuffer. Increments position().