IllegalAccessError

[jeanlazarou]

I tried to instrument javax.swing.JPopupMenu and when I create an JPopupMenu instance, next Exception is thrown:
> java.lang.IllegalAccessError: tried to access method > javax.swing.SwingUtilities.appContextGet
> (Ljava/lang/Object;)Ljava/lang/Object;
> from class javax.swing.JPopupMenu
>
> at javax.swing.JPopupMenu.
> getDefaultLightWeightPopupEnabled
> (JPopupMenu.java:140)
>
> at javax.swing.JPopupMenu.
> (JPopupMenu.java:165)

The code that modified the class (in a custom class loader) looks like:

> CtClass cc = pool.get(name);
> CtMethod m = cc.getDeclaredMethod(...);
> m.insertBefore(...);
> byte[] b = cc.toBytecode();
> Class c = defineClass(name, b, 0, b.length);
> return c;

Can some help?

Thanks,
Jean

[chiba]

Can you try an unmodified JPopupMenu?

> CtClass cc = pool.get(name);
> byte[] b = cc.toBytecode();
> Class c = defineClass(name, b, 0, b.length);
> return c;

This simply loads JPopupMenu as is. If an exception
is still thrown, the problem is because JPopupMenu
is loaded by a class loader different from one loading
javax.swing.SwingUtilities.appContextGet. This
prohibits JPopupMenu from accessing package
methods in SwingUtilities.

Please read Section 4 of the tutorial.

Chiba

[jeanlazarou]

As is stated in javassist.Loader:

/* The swing components must be loaded by a system
* class loader.
* javax.swing.UIManager loads a (concrete) subclass
* of LookAndFeel by a system class loader and cast
* an instance of the class to LookAndFeel for
* (maybe) a security reason. To avoid failure of
* type conversion, LookAndFeel must not be loaded
* by this class loader.
*/

I cannot do what I want...

The only think I could do is instrument the compiled
class and then use : java -Xbootclasspath

Jean