FinalOverridingIllusion.java

package thinkinginjava.reusing;

// It only looks like you can override
// a private or private final method.
import static thinkinginjava.util.Print.*;

class WithFinals {
	// Identical to "private" alone:
	private final void f() {
		print("WithFinals.f()");
	}

	// Also automatically "final":
	private void g() {
		print("WithFinals.g()");
	}
}

class OverridingPrivate extends WithFinals {
	private final void f() {
		print("OverridingPrivate.f()");
	}

	private void g() {
		print("OverridingPrivate.g()");
	}
}

class OverridingPrivate2 extends OverridingPrivate {
	public final void f() {
		print("OverridingPrivate2.f()");
	}

	public void g() {
		print("OverridingPrivate2.g()");
	}
}

public class FinalOverridingIllusion {
	public static void main(String[] args) {
		OverridingPrivate2 op2 = new OverridingPrivate2();
		op2.f();
		op2.g();
		// You can upcast:
		OverridingPrivate op = op2;
		// But you can't call the methods:
		// ! op.f();
		// ! op.g();
		// Same here:
		WithFinals wf = op2;
		// ! wf.f();
		// ! wf.g();
	}
} /*
 * Output: OverridingPrivate2.f() OverridingPrivate2.g()
 */// :~