!7 lib 1400554 // javassist import javassist.ClassPool; import javassist.CtClass; import javassist.CtMethod; p { ClassPool pool = ClassPool.getDefault(); CtClass cc = pool.makeClass("User123"); // The method part doesn't work yet /*CtClass cString = pool.get("java.lang.String"); var method = new CtMethod(cString, "hello", new CtClass[0], cc); method.setModifiers(Modifier.PUBLIC | Modifier.STATIC); cc.addMethod(method);*/ //Class c = cc.toClass(); byte[] bytes = cc.toBytecode(); var cl = new InMemoryClassLoader(myClassLoader()); Class c = cl.defineAClass("User123", bytes); print(c); }