How to do method chaining in Java? o.m1().m2().m3().m4()

Question

I\'ve seen in many Java code notation that after a method we call another, here is an example.

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Answer 1

Adding return this; would surely help in chaining for this class but fail for sub-classes.

If you want to have the chaining behaviour inherited to the sub-classes also then change your class signature as below:

Class SuperClass < SubClass extends SuperClass >{}

This way all sub-classes will inherit method chaining.

Example:

public class SuperClass {

    public SubClass testMethod(){
        return (SubClass)this;
    }

    public static void main(String[] args) {
        SuperClass superClass = new SuperClass();
        superClass.testMethod().testMethod().testMethod();
        System.out.println(superClass.toString());
    }

}