我想你可能会追求的是 ByteBuffer ：

I think what you may be after is a ByteBuffer:

ByteBuffer pump_on_buf = ...
pump_on_buf.putInt(0);
pump_on_buf.putInt(0);
pump_on_buf.putShort(21);
pump_on_buf.putShort(96);
pump_on_buf.putInt(512);
byte[] pump_on = pump_on_buf.array();