CODEWITHSUNDEEP
javainheritancestatic
Adon Smith
Adon Smith

Reputation: 1889

How can i call child's static method from parent's static method?

I have a Base class 

public class BaseStatic {
    public static String fname = "Base";
    public static String lname = "Static";

    public static void send(){
        System.out.println("BaseStatic send");
        sendTo();
    }

    public static void sendTo(){
        //How to call from here Child's static method.
        System.out.println("BaseStatic sendTo");
    }
}

and I have a Child Class which extends it.

public class FirstStatic extends BaseStatic {
    public static String fname = "First";
    public static String lname = "Static";

    public static void sendTo(){
        System.out.println("FirstStatic sendTo");
    }
}

Now there is an Main class 

public class Main {
    public static void main(String args[]){
        FirstStatic.send();
    }
}

Does java provide me a way so that when i call from Main method FirstStatic.send , It goes to send method of BaseStatic , from there i can call sendTo method of FirstStatic rather than calling sendTo method of BaseStatic

Upvotes: 4

Views: 3083

Answers (2)

unigeek
unigeek

Reputation: 2826

The commented-out sendTo() method here would have the effect of hiding the implementation of sendTo() in the base class.

public class BaseStatic {
    public static String fname = "Base";
    public static String lname = "Static";

    public static void send(){
        System.out.println("BaseStatic send");
        sendTo();
    }

    public static void sendTo(){
        //How to call from here Child's static method.
        System.out.println("BaseStatic sendTo");
    }

    public static void main(String[] args) {
        FirstStatic.sendTo();
    }
}

class FirstStatic extends BaseStatic {
    public static String fname = "First";
    public static String lname = "Static";

    //public static void sendTo(){
    //    System.out.println("FirstStatic sendTo");
    //}
}

You can do the following, of course, but the net effect is identical to the code shown above. If you need polymorphism, you'll need to do away with the statics--probably a good idea, anyway!

public class BaseStatic {
    public static String fname = "Base";
    public static String lname = "Static";

    public static void send(){
        System.out.println("BaseStatic send");
        sendTo();
    }

    public static void sendTo(){
        //How to call from here Child's static method.
        System.out.println("BaseStatic sendTo");
    }

    public static void main(String[] args) {
        FirstStatic.sendTo();
    }
}

class FirstStatic extends BaseStatic {
    public static String fname = "First";
    public static String lname = "Static";

    public static void sendTo(){
        BaseStatic.sendTo();
    }
}

EDIT: These examples are structured such that you can easily do the following to verify the behavior.

javac BaseStatic.java
java BaseStatic

Upvotes: 0

Eran
Eran

Reputation: 394126

There is no polymorphism for static methods. Therefore, in order to call a static method x of class A, you must write A.x().

FirstStatic.send() will call BaseStatic's send only because FirstStatic has no static send method. However, BaseStatic's send will always call BaseStatic's sendTo, unless you explicitly call FirstStatic.sendTo().

Upvotes: 5

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