Description Mark Wilkinson 2004-11-02 08:18:47 EST

The compiler seems to generate the wrong code (or different from jdk 1.4.2_06,
at least) for the default constructor in private nested classes. Given the
following classes defined over two files:

package scribble;

public class Bar {
    public static void main(String[] args) throws Exception {
        Foo foo = new Foo();
        foo.frob(Baz.class);
    }

    private static class Baz {
    }
}

public class Foo {
    public void frob(Class cls) throws Exception {
        Object o = cls.newInstance();
    }
}

Compiling and running with the JDK gives:

Exception in thread "main" java.lang.IllegalAccessException: Class scribble.Foo
can not access a member of class scribble.Bar$Baz with modifiers "private"
        at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:57)
        at java.lang.Class.newInstance0(Class.java:302)
        at java.lang.Class.newInstance(Class.java:261)
        at scribble.Foo.frob(Foo.java:5)
        at scribble.Bar.main(Bar.java:10)

Compiling with Eclipse and running with the JDK gives no error.

Comparing the output of javap shows why. javac gives us this:

Compiled from "Bar.java"
class scribble.Bar$Baz extends java.lang.Object{
    private scribble.Bar$Baz();
}
 
while Eclipse's compiler gives us this:

Compiled from "Bar.java"
class scribble.Bar$Baz extends java.lang.Object{
    scribble.Bar$Baz();
}
 
Interestingly, the same code is generated even if Baz has an explicit private
constructor.