Question

I have a client server application and for testing purposes I need to start the client in a test method by calling

Client.main();

That creates some new thread. Now I need to wait until that thread is completed before performing assertions in my test. How do I know when this happens? Alternatively, how do I know, which thread was started by the call (the client can create other threads too).

Answer 1

Calling main programmatically won’t start a new thread on its own. That would only happen if the main method has code to explicitly start a new thread. If that’s the case, you should change Client to provide access to this thread in some form, so you can call join() on it. (Calling Thread.join() is the standard way of waiting for a thread to finish.)

Does Client.main() perform any tasks other than starting a new thread? If not, it would probably be simpler for your tests to just call whatever run() method the new thread will end up running, and making the test single-threaded as far as possible.