Question

I have a abstract class named Vehicle:

public abstract class Vehicle {

    public void run() {
        addToRunningVehicleList();
    }

}

I want that every classes that extends Vehicle must call super.run() if they override run method. For example:

public class Car {

    @Override
    public void run() { // Error here because does not call super.run()
        carRunningAnimation();
    }

}

Is it possible in OOP concept, or Java/C#?

EDIT: Following Petar Ivanov, I have this code:

public abstract class Vehicle {

    public final void run() {
        Log.e("Run", "Add To List");
        runImp();
    }

    public void runImp() {}

}

public class Car extends Vehicle {

    @Override
    public void runImp() {
        Log.e("Run", "Run in Car");
    }

}

However, it’s not very good for public APIs. When extending Vehicle, the end-users must override runImp, but then they have to call run() method, so I have to make public both run and runImp, which make nothing better.

Answer 1

Here is how I would do it (C#):

public abstract class Vehicle {

    public void Run() {
        //code that will always run
        addToRunningVehicleList();

        //code that can be overriden
        RunImpl();
    }

    protected virtual void RunImpl() { }
}

public class Car : Vehicle {

    protected override void RunImpl() {
        carRunningAnimation();
    }

}

You can make the RunImpl protected to make sure it can’t be called outside the subclasses of Vehicle.