Question

I have a static Factory class that throws an exception if not inited before a call is made. What I don’t understand why eclipse is yelling at me for throwing the exception (it demands that I surround the toss in a try/catch) in the Factory, but in another class where I throw an UnsupportedOperationException, eclipse is just fine.

Is there a rule I am unaware of that I’m violating?

My static call (source of the issue):

public static Object createObject() {
    if (CONTEXT == null)
        throw new InstantiationException("Factory not inited.");
    // ...
}

Edit: I realise this would probably be better suited as a singleton instead of a static class, but the question still stands.

Answer 1

You need to look at the difference between Checked exceptions and Unchecked exceptions.

http://docs.oracle.com/javase/tutorial/essential/exceptions/catchOrDeclare.html

If the exception you throw is derived from RuntimeException, it is Unchecked and doesn’t need to be declared/handled explicitly. All others must be.