Why protected method is not accessible from subclass?

Question

Consider the following code snippets:

package vehicle;

public abstract class AbstractVehicle {
    protected int speedFactor() {
        return 5;
    }
}

pack         


        

Answer 1

Back in my SCJP for Java 1.5 days, one thing that I used to remember was be wary of superclass reference variables. It isn't quite as surprising to see this now and one thing why this gets confusing is the rule is protected is visible to subclass or same package. What if it's both subclass and different package?

If you create another package, and do

package yetAnotherPackage;

import car.SedanCar;

public class Main {

    public static void main(String[] args) {
        new SedanCar().speedFactor();
    }

}

you'll see that

The method speedFactor() from the type AbstractVehicle is not visible

Looks like the rule just propagates. As long as you have a subclass and try to access the protected method within the package of the subclass (or if no subclass, then the package of the parent), you should be good.