Navgeet Agrawal [https://community.jboss.org/people/navgeet] created the discussion "IllegalAccessError when using an instrumented class" To view the discussion, visit: https://community.jboss.org/message/824470#824470 -------------------------------------------------------------- Hi all, I am trying to instrument https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Compi... https://github.com/clojure/clojure/blob/master/src/jvm/clojure/lang/Compi... I am using the following code: ClassPool cp = ClassPool.getDefault(); CtClass ctClazz = cp.get("clojure.lang.Compiler"); ctClazz.addMethod(CtNewMethod.make("public String foo (){return \"foo\"; }", ctClazz)); return ctClazz.toClass(); I am calling getDeclaredMethod on the returned class and invoke on the method to call foo() which throws: IllegalAccessError tried to access class clojure.lang.Compiler$DefExpr$Parser from class clojure.lang.Compiler  clojure.lang.Compiler.<clinit> (Compiler.java:102) Javassist's docs state that it does not work with inner classes, which I suspect to be the problem here. Or rather it could be a ClassLoader problem. Unfortunately I know little about classloaders. Any pointers would be appreciated. Thanks! -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/824470#824470] Start a new discussion in Javassist at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]