I'm designing a system with different types of components, and I'm trying to decide whether to use polymorphism or instanceof checks for handling type-specific behavior.

I see two possible approaches:

• Polymorphism Approach – Define all possible methods in a base class (even if only some subclasses override them).
• instanceof Approach – Only define relevant methods in specific subclasses and check types before calling them.

Example with polymorphism

abstract class Component {
    // Default implementations (may do nothing)
    void specialAction() {}  
}

class GeneralComponent extends Component {
    // Doesn't need to override specialAction()
}

class SpecialComponent extends Component {
    @Override
    void specialAction() {
        System.out.println("Special action executed!");
    }
}

// Usage
void handleComponent(Component component) {
    component.specialAction(); // Will only do something if overridden
}

Example with instanceof

In this approach, methods exist only in the relevant subclasses, and we check the type before calling them.

abstract class Component {}

class GeneralComponent extends Component {}

class SpecialComponent extends Component {
    void specialAction() {
        System.out.println("Special action executed!");
    }
}

// Usage
void handleComponent(Component component) {
    if (component instanceof SpecialComponent) {
        ((SpecialComponent) component).specialAction();
    }
}

I understand that excessive use of instanceof is generally discouraged, but adding methods to the base class that aren't shared among all the subclasses doesn't seems to be a good design choice either.