Question

I’m reading this Java SCJP book and I came across this:

The protected and default access control
levels are almost identical, but with one critical difference. A
default member may be accessed only if the class accessing the member
belongs to the same package, whereas a protected member can be
accessed (through inheritance) by a subclass even if the subclass is
in a different package.

So I decided to test out the protected point.

I have a super-class in a package

package scjp;

public class Token {

    protected int age = 6; //This is the protected class-level variable.

    public Token(String name){
        this.name = name;
    }
    public Token(String name, int age){
        this.name = name;
        this.age = age;
    }

    public String getName(){
        return this.name;
    }

    public int getAge(){
        return this.age;
    }
}

The I have a sub-class in another package;

package pack;

import scjp.Token;

public class son extends Token{

    public static void main(String[] args) {
       System.out.println(Token.age);
    }

}

As you can see I’m trying to access the protected class-level integer variable age in the super-class.

But I get this error:

 age has protected access in scjp.Token
        at pack.son.main(son.java:11)
Java Result: 1

So, what’s going wrong?

Answer 1

You are trying to access a non static protected member of your super class with class reference..

public static void main(String[] args) {
       Token t = new Token("somehting");
       System.out.println(t.age);
    }

will compile and work fine.