Name: bsC130419 Date: 06/19/2001


java version "1.4.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta-b65)
Java HotSpot(TM) Client VM (build 1.4.0-beta-b65, mixed mode)

and

java version "1.3.1"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1-b24)
Java HotSpot(TM) Client VM (build 1.3.1-b24, mixed mode)

There is an inconsistency from previous versions of java (<= 1.3.1) when using
reflection to call methods on classes that are protected and in a different
package. Here is some code that demonstrates this.

package p1;
import java.lang.reflect.*;
import p2.*;

public class x extends y {
    public x() {
        z z = new z();
        z.callZ();

        try {
            Class [] classes = {};
            Object [] args = {};
            Method m = z.getClass().getMethod("callZ", classes);
            m.invoke(z, args);
        } catch(Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String [] args) {
        x x = new x();
    }
}

and

package p2;

public class y {
    public y() {}
    protected class z {
        public z() {}
        public void callZ() {
            System.out.println("Called Z");
        }
    }
}

The key is that x extends y so it should inherit and be able to use the
protected class z. We can see this is true with z.callZ() directly. However,
this behavior is no longer valid when reflection is used to invoke callZ()
using Method's invoke(). It will work if the classes are in the same package,
regardless though, since x is a child of y, it should have access to all of y's
public and protected fields and methods. We can see this behavior correctly
work in all previous versions of the JDK, however the 1.4 beta no longer allows
this and throws a java.lang.IllegalAccessException, ie:

1.4:
$ java p1.x
Called Z
java.lang.IllegalAccessException: Class p1.x can not access a member of class p2
.y$z with modifiers "public"
        at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:50)
        at java.lang.reflect.Method.invoke(Method.java:300)
        at p1.x.<init>(x.java:14)
        at p1.x.main(x.java:21)

1.3.1 and prior:
$ java p1.x
Called Z
Called Z

Perhaps this is just a Windows bug as I have not verified it on other platforms
yet, but I would strongly suspect it is not.

If 1.4 implements the correct behavior per the JLS, then this may be
troublesome to developers who have written code (albiet invalid code) that not
only conforms to this bug, but requires it. If this is the case, Sun needs to
document this in large bold red letters in the reflection section of the 1.4
documentation.
(Review ID: 126933)
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