Question

I want that when a child class overrides a method in a parent class, the super.method() is called in that child method.

Is there any way to check this at compile time?
If not, how would I go about throwing a runtime exception when this happens?

Answer 1

There’s no way to require this directly. What you can do, however, is something like:

public class MySuperclass {
    public final void myExposedInterface() {
        //do the things you always want to have happen here

        overridableInterface();
    }

    protected void overridableInterface() {
        //superclass implemention does nothing
    }
}

public class MySubclass extends MySuperclass {
    @Override
    protected void overridableInterface() {
        System.out.println("Subclass-specific code goes here");
    }
}

This provides an internal interface-point that subclasses can use to add custom behavior to the public myExposedInterface() method, while ensuring that the superclass behavior is always executed no matter what the subclass does.