[java] Java: Calling a super method which calls an overridden method

The keyword super doesn't "stick". Every method call is handled individually, so even if you got to SuperClass.method1() by calling super, that doesn't influence any other method call that you might make in the future.

That means there is no direct way to call SuperClass.method2() from SuperClass.method1() without going though SubClass.method2() unless you're working with an actual instance of SuperClass.

You can't even achieve the desired effect using Reflection (see the documentation of java.lang.reflect.Method.invoke(Object, Object...)).

[EDIT] There still seems to be some confusion. Let me try a different explanation.

When you invoke foo(), you actually invoke this.foo(). Java simply lets you omit the this. In the example in the question, the type of this is SubClass.

So when Java executes the code in SuperClass.method1(), it eventually arrives at this.method2();

Using super doesn't change the instance pointed to by this. So the call goes to SubClass.method2() since this is of type SubClass.

Maybe it's easier to understand when you imagine that Java passes this as a hidden first parameter:

public class SuperClass
{
    public void method1(SuperClass this)
    {
        System.out.println("superclass method1");
        this.method2(this); // <--- this == mSubClass
    }

    public void method2(SuperClass this)
    {
        System.out.println("superclass method2");
    }

}

public class SubClass extends SuperClass
{
    @Override
    public void method1(SubClass this)
    {
        System.out.println("subclass method1");
        super.method1(this);
    }

    @Override
    public void method2(SubClass this)
    {
        System.out.println("subclass method2");
    }
}



public class Demo 
{
    public static void main(String[] args) 
    {
        SubClass mSubClass = new SubClass();
        mSubClass.method1(mSubClass);
    }
}

If you follow the call stack, you can see that this never changes, it's always the instance created in main().

Examples related to java

Under what circumstances can I call findViewById with an Options Menu / Action Bar item? How much should a function trust another function How to implement a simple scenario the OO way Two constructors How do I get some variable from another class in Java? this in equals method How to split a string in two and store it in a field How to do perspective fixing? String index out of range: 4 My eclipse won't open, i download the bundle pack it keeps saying error log

Examples related to inheritance

How to extend / inherit components? Inheritance with base class constructor with parameters Class is not abstract and does not override abstract method Why not inherit from List<T>? Can an interface extend multiple interfaces in Java? How to call Base Class's __init__ method from the child class? How should I have explained the difference between an Interface and an Abstract class? JavaScript OOP in NodeJS: how? When do I have to use interfaces instead of abstract classes? C++ calling base class constructors

Examples related to overriding

How to underline a UILabel in swift? How to 'update' or 'overwrite' a python list maven command line how to point to a specific settings.xml for a single command? How to override the properties of a CSS class using another CSS class What is the difference between dynamic and static polymorphism in Java? Overriding css style? Android Overriding onBackPressed() What is the 'override' keyword in C++ used for? Why do we have to override the equals() method in Java? Can overridden methods differ in return type?

Examples related to super

Equivalent of Super Keyword in C# super() raises "TypeError: must be type, not classobj" for new-style class Java: Calling a super method which calls an overridden method When do I use super()? super() in Java What is PECS (Producer Extends Consumer Super)? super() fails with error: TypeError "argument 1 must be type, not classobj" when parent does not inherit from object Understanding Python super() with __init__() methods What does 'super' do in Python?