Given the following example:
String f="FF00000000000000";
byte[] bytes = DatatypeConverter.parseHexBinary(f);
String f2= new String (bytes);
I want the output to be FF00000000000000 but it's not working with this method.
1 Answer
You're currently trying to interpret the bytes as if they were text encoded using the platform default encoding (UTF-8, ISO-8859-1 or whatever). That's not what you actually want to do at all - you want to convert it back to hex.
For that, just look at the converter you're using for the parsing step, and look for similar methods which work in the opposite direction. In this case, you want printHexBinary:
String f2 = DatatypeConverter.printHexBinary(bytes);
The approach of "look for reverse operations near the original operation" is a useful one in general... but be aware that sometimes you need to look at a parallel type, e.g. DataInputStream / DataOutputStream. When you find yourself using completely different types for inverse operations, that's usually a bit of a warning sign. (It's not always wrong, it's just worth investigating other options.)
DatatypeConverter? Possibly it has a reverse method?