Why I'm facing with 'clone() has protected access in java.lang.Object' compiler error?

Object’s clone method is protected, therefore it can be accessed in sub classes (class A), so why am I getting ‘clone() has protected access in java.lang.Object’ compiler error? I thought, that all Java classes are sub classes of Object. Thanks in advance.

The code below raises the compiler error:

public class A {
    public static void main(String[] args) {
        Object o = new Object();
        o.clone();//error
    }
}

But this one compiles perfectly, don’t they have the same semantics tho?

public class A {
    protected void foo() {

    }
}

public class B extends A {
    public static void main(String[] args) {
        A a = new A();
        a.foo();
    }
}

>Solution :

No, they don’t.

protected means 2 things:

• It’s like package, _and that explains why your second snippet can call foo(). It’s not about the fact that B extends A, it’s that A is in the same package as B.
• Subclasses can invoke it.. on themselves only. Trivially (but this doesn’t work if its final), you can simply override it, implement it as return super.clone(); and now you can call it just fine.