how can i use unsigned in java

Question

I need convert integer to byte and write byte in file but when i convert a number larger than 128 to byte in convert to a negative number. I need to use unsigned char but i don't know how. in c++ we write unsigned but how is it in java?

Java doesn't have `unsigned`. Could you be more specific about what you're trying to do, and the results you're getting? — David Thornley, Jun 23 '11 at 20:01

score 5 · Answer 1 · answered Jun 23 '11 at 20:01

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Java doesn't have unsigned types by default but you can workaround it, see Java and unsigned int, unsigned short, unsigned byte, unsigned long, etc. (Or rather, the lack thereof)

answered Jun 23 '11 at 20:01

ismail

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score 2 · Answer 2 · edited May 23 '17 at 11:48

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Java doesn't have unsigned types. I suggest you use a short, since it can accommodate all the values available to an unsigned char in languages like C and C++.

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edited May 23 '17 at 11:48

Community

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answered Jun 23 '11 at 20:00

Martin Törnwall

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score 1 · Accepted Answer · answered Jun 23 '11 at 20:15

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Writing bytes is not a problem, it doesn't matter whether you use write(int) or writeByte(byte) since the data written is still the same whether the byte is signed or unsigned. Reading bytes using read() also isn't a problem, because it returns unsigned bytes. Only when you're reading into a byte array do you need to be careful, because then you have to remember to mask each byte with 0xFF when you use it.

answered Jun 23 '11 at 20:15

Neil

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This will generally work, unless you happen to be processing data which came from (or is going to) a system with different endian-ness – Edwin Buck Jun 23 '11 at 20:18

how can i use unsigned in java

3 Answers3