Returning error codes from a method

Question

I'd like to ask something confuses me a lot. Here is the scenario, lets say I have a method preparePayload that takes some argument like messageType, destAddr etc. The duty of method is construct a fully payload (with headers, prefixes etc). Here is the problem, I want to return statusCode (which is enum, like STATUS_OK,STATUS_INVALID_DEST, STATUS_INVALID_MSG_TYPE etc.), and than respect to return status I'd like to implement my logic. But if there is no error (STATUS_OK), I need the prepared payload to move on. So my method should return eighter payload or status code.

In C language, simply sending payload buffer address as an argument to preparePayload method solves the problem perfectly. When the method returns, simply reading payload from the buffer address and moving on the application works. How can I implement this kind of logic in Java?

In addition, preparePayload method is just an example I gave, so the methods I implemented may return String, int[], some class object that I wrote etc. I mean, the type of object that method should return in success case may vary.

Any suggestion will very welcome.

Answer 1

Besides changing to exceptions, there is one more hackish way to allow for "input/output" parameters, like:

public ResultEnum preparePayLoad(List<PayLoad> toPrepare, ... other args) {
...
  PayLoad newThing = ...
...
  toPrepare.add(newThing);
  return someEnum;
}

So, you could use such an approach to "emulate" the "C style"; but the more Java/OO would be

public PayLoad preparePayLoad(args) {
...
  PayLoad newThing = ...
...
  return newThing;
}

and to throw (checked or unchecked) exceptions for error situations.