Question

Compare these two methods:

void foo() throws SomeSuperException {
    try {
        //...
    } catch (SomeSuperException e) {
        if (e instanceof SomeSubException) {
            throw e;
        }
    }
}

void bar() throws SomeSubException {
    try {
        //...
    } catch (SomeSuperException e) {
        if (e instanceof SomeSubException) {
            throw (SomeSubException) e;
        }
    }
}

Aside from the method signatures (bar can declare throws SomeSubException instead of throws SomeSuperException), is there any practical difference between the two methods?

To be clear: I’m aware that this is a horrible approach to exception handling, and should not be done!

Answer 1

The difference is that in the first case, externally the caller doesn’t know about your specific SomeSubException, so some detail is lost in translation.