Question

I am using a technology called DDS and in the IDL, it does not support int. So, I figured I would just use short. I don’t need that many bits. However, when I do this:

short bit = 0;
System.out.println(bit);
bit = bit | 0x00000001;
System.out.println(bit);
bit = bit & ~0x00000001;
bit = bit | 0x00000002;
System.out.println(bit);

It says “Type mismatch: Cannot convert from int to short”. When I change short to long, it works fine.

Is it possible to perform bitwise operations like this on a short in Java?

Answer 1

When doing any arithmetic on byte, short, or char, the numbers are promoted to the wider type int. To solve your problem, explicitly cast the result back to short:

bit = (short)(bit | 0x00000001);

Links:

• Stack Overflow: Promotion in Java?
• Java Language Specification section 5.6: http://java.sun.com/docs/books/jls/second_edition/html/conversions.doc.html#26917