CODEWITHSUNDEEP
javaoop
Shailendra Singh Rajawat
Shailendra Singh Rajawat

Reputation: 8242

how to return a child method from its parent method?

Class parent {

protected void myMethod() {
 if(someCodition) {
 //return this as well as child's myMethod.
  }
}

Class child extends Parent {

@override
protected void myMethod() {
super.myMethod();
 //code below this line should not execute if someCondition.
 //want parent to handle all this
  }
}

Please don't suggest to take some boolean flag kind of thing in parent class and check it in child. actually child class will be used by other developers and i dont want them to take care about any such condition, so want to exit from parent itself.

I am fully aware that it is violation of Abstraction principle of oops, but its my need to violate .

Updating

PS: to call myMethod() is not in either child or parent's control , so can not create a separate method as mentioned in one answer . actually its and API method, so system will execute it automatically as per need, and i can not stop to call it.

Upvotes: 0

Views: 989

Answers (1)

amit
amit

Reputation: 178441

You are probably looking for template method pattern [or some variation of it]

The user will override the protected method myTemplateMethod(), and myMethod() will not be overriden.

myMethod() will invoke super.myMethod() [it was not overriden so actually the super will be invoked immidiately], and the super will invoke [if conditions are met] myTemplateMethod()

Something along the lines of [pseudo code]:

abstract Class parent {

protected abstract void myTemplateMethod();

protected final void myMethod() {
 if(someCodition) {
    myTemplateMethod();
  }
}

Class child extends Parent {

@override
protected void myTemplateMethod() {
 //code that will be invoked only if someCodition is met
  }
}

Upvotes: 3

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