Java class inheritance, private fields accessible in subclass, why?

I have code very much like the following.

package my.pkg;

public abstract class X {
    private CapableField field;

    public abstract void doSomething();

    public X(CapableField fie开发者_开发知识库ldValue) {
        this.field = fieldValue;
    }
}

And:

package my.pkg.sub;

public class Y extends my.pkg.X {
    public void doSomething() {
        this.field.doSomething();
    }
}

Why is this even legal code in Java? I thought "private" meant that the field will not be directly accessible in subclasses, and that this was a fairly basic tenet of class inheritance. Making X concrete instead of abstract changes nothing.

What do I do if I specifically want a field, or member function, to be accessible only inside the class where it is defined, and not in some random subclass of the defining class?

This is not true. Most likely you've actually definied Y as an inner class. This way the private fields of the outer class are indeed visible like that.

Doesn't compile for me too! I suspect your Java implementation.

This is impossible. May be you missed something when you explain your question.

private members are not visible in inheritance except in inner class scope. If you want them to be accessed by the subclass then declare them as protected. or use setters and getters.

and in your code you used package keyword in your package declaration which is not allowed and gives compilation error.

Make sure that your classes in two different files. for example X.java and Y.java and y not an inner class