CODEWITHSUNDEEP
javagenericsmethodsgeneric-programming
tmsblgh
tmsblgh

Reputation: 527

How to use generic function parameter

I would like to use one method for two types and I tried like this:

private <T extends Base> boolean isNeeded(String name, T receivedItem) {
    Base item = null;
    if (receivedRequest.getClass().equals(Derived1.class)) {
        item = (Derived1) receivedItem;
    } else if (request.getClass().equals(Derived2.class)) {
        item = (Derived2) receivedItem;
    }
    callMethodDoSomething(item.getData().getSpecificData());
}

But I do not know how to call a method which is only in the derived classes. Which is the best and safest way to do it?

Upvotes: 0

Views: 84

Answers (2)

user8654079
user8654079

Reputation:

Why not just

boolean isNeeded(Base base) { 
    return callMethodDoSomething(base.getData().getSpecificData());
}

(Also skip the 'name' parameter since it is not used)

Upvotes: 1

Leo Aso
Leo Aso

Reputation: 12493

That's what method overloading is for.

boolean isNeeded(String name, Derived1 item) { 
   return callMethodDoSomething(
        item.getData().getSpecificData());
}

boolean isNeeded(String name, Derived2 item) { 
   return callMethodDoSomething(
        item.getData().getSpecificData());
}

Upvotes: 1

Related Questions