Question

Code:

public void doSomethingOrThrowUncheckedException()
{

    Thread worker = new Thread(new Runnable() {
            public void run() {
                try {
                    myObject.doSomething()
                } catch(CheckedException e) {
                    new UncheckedException ();
                }
            }
        });
    worker.start();
}

Explanation

I want to perform some work in another thread that can throw a checked exception.

I cannot wait for this work to finish and I want the method caller to know if something went wrong with this work since the new thread is not able to handle the exception properly.

Is there a mechanism I can use?

Answer 1

It depends on what you mean by the caller knowing that something went wrong. A couple of options come to mind immediately.

• The worker thread can set an error flag. The disadvantage is that the calling thread will need to check the flag to know that something went wrong. (There can also be a flag for success; as long as neither is set, the calling thread knows that the worker is still working.

• The worker thread can call an error method. The disadvantage is that the call will take place in the worker thread. On the other hand, this provides a place to take positive action. The Observer pattern might be useful here (although I think Java’s implementation is terrible).