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Groups > comp.lang.java.programmer > #7036

virtual method lookup and accessibility

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The language spec section 15.12.4.4 "Locate Method to Invoke" (http://
java.sun.com/docs/books/jls/third_edition/html/
expressions.html#15.12.4.4) describes how run-time virtual method
lookup works, and then says:

"The above procedure will always find a non-abstract, accessible
method to invoke, provided that all classes and interfaces in the
program have been consistently compiled."

Is this true? Specifically, is the method that's invoked always
"accessible" from the class containing the method invocation
expression?

I think this is a counter-example:

package A;
public class C {
    protected void f() {
	System.out.println("Hello from C");
    }
}

package B;
public class D extends A.C {
    protected void f() {
	System.out.println("Hello from D");
    }
}

package A;
public class E {
    public static void main(String args[]) {
	C c = new B.D();
	c.f();
    }
}

If I compile and run this I get:

$ javac ?/*.java
$ java A.E
Hello from D

So A.E has invoked B.D.f(); but B.D.f() is not accessible from A.E,
because it is protected and in a different package.

Is this a bug in the language spec?

Thanks,
Jay.

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Thread

virtual method lookup and accessibility Jay Foad <jay.foad@gmail.com> - 2011-08-12 02:21 -0700
  Re: virtual method lookup and accessibility kedar mhaswade <kedar.mhaswade@gmail.com> - 2011-08-12 07:20 -0700
  Re: virtual method lookup and accessibility Lew <lewbloch@gmail.com> - 2011-08-12 06:55 -0700
  Re: virtual method lookup and accessibility Jay Foad <jay.foad@gmail.com> - 2011-08-12 08:27 -0700
    Re: virtual method lookup and accessibility Lew <lewbloch@gmail.com> - 2011-08-12 14:46 -0700
  Re: virtual method lookup and accessibility Roedy Green <see_website@mindprod.com.invalid> - 2011-08-12 14:43 -0700

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