Literal Syntax For byte[] arrays using Hex notation..?

As the other answered already said, byte is a signed type in Java. The range is from -128 to 127 inclusive. So 0xff is equal to -0x01. You can use 0xff instead of -0x01 if you add a manual cast:

byte[] rawbytes={0xa, 0x2, (byte) 0xff};

There is one more possibility by declaring a helper function with variable arguments. This may be preferable if you need to declare multiple byte arrays.

Example code

public static byte[] toBytes(int... ints) { // helper function    byte[] result = new byte[ints.length];    for (int i = 0; i < ints.length; i++) {        result[i] = (byte) ints[i];    }    return result;}public static void main(String... args) {    byte[] rawbytes = toBytes(0xff, 0xfe); // using the helper    for (int i = 0; i < rawbytes.length; i++) {        System.out.println(rawbytes[i]); // show it works    }}

"0xFF" is an int literal for the decimal value 255, which isn't representable as a byte.

For now, you'll need to cast it to a byte to tell the compiler you really mean -1, like this:

byte[] rawbytes = { 0xA, 0x2, (byte) 0xFF };

It was proposed to add a new byte literal syntax (y or Y suffix) to Java 7. Then you would have been able to write:

byte[] rawbytes = { 0xA, 0x2, 0xFFy };

However, this proposal was not included in the "omnibus proposal for improved integral literals," so we be stuck with the cast forever.