Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
324 views
in Technique[技术] by (71.8m points)

java - Require override of method to call super

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?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

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.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...