public static ByteBuffer allocateDirect(int capacity) {
        ByteBuffer buf = ByteBuffer.allocateDirect(capacity);
        buf.limit(0);
        return buf;
    }
public static ByteBuffer allocateDirect ( int capacity ) { ByteBuffer buf = ByteBuffer . allocateDirect ( capacity ) ; buf . limit ( 0 ) ; return buf ; }
Allocate ByteBuffer in flush mode.
The position and limit will both be zero, indicating that the buffer is
empty and in flush mode.

@param capacity capacity of the allocated ByteBuffer
@return Buffer