2个字节来缩短java [英] 2 bytes to short java

问题描述

我正在读取来自serialport的133长度数据包，最后2个字节包含CRC值，2个字节值我使用java制作单个（我认为）。
这就是我所做的，

i'm reading 133 length packet from serialport,last 2 bytes contain CRC values,2 bytes value i've make single(short i think) using java. this what i have done,

short high=(-48 & 0x00ff);
short low=80;

short c=(short) ((high<<8)+low);

但是我没有得到正确的结果，是否因为签名有问题？
我怎么能解决这个问题，PLZ帮助我我遇到麻烦

but i'm not getting correct result,is it problem because signed valued? how can i solve this problem,plz help me i'm in trouble

推荐答案

记住，你不要如果你对细节不太熟悉的话，必须把自己束缚在变速之中。您可以使用ByteBuffer来帮助您：

Remember, you don't have to tie yourself in knots with bit shifting if you're not too familiar with the details. You can use a ByteBuffer to help you out:

ByteBuffer bb = ByteBuffer.allocate(2);
bb.order(ByteOrder.LITTLE_ENDIAN);
bb.put(firstByte);
bb.put(secondByte);
short shortVal = bb.getShort(0);

反之亦然，你可以卖空，然后拉出字节。

And vice versa, you can put a short, then pull out bytes.

顺便说一下，按位运算会自动将操作数提升到至少int的宽度。实际上并没有不允许超过7位的字节移位这一概念，而其他谣言似乎已经过去了。

By the way, bitwise operations automatically promote the operands to at least the width of an int. There's really no notion of "not being allowed to shift a byte more than 7 bits" and other rumours that seem to be going round.

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