When extending java.lang.ClassLoader, I can't seem to execute defineClass. Here's my test case showing the issue.
var superLoader = Java.super(new (Java.extend(java.lang.ClassLoader))(){}); // defineClass on the super object doesn't exist for some reason print("defineClass: " + (superLoader.defineClass !== undefined)); // definePackage is protected, but isn't undefined, so that isn't the issue print("definePackage: " + (superLoader.definePackage !== undefined)); and here's the output of "java -version": java version "1.8.0_161" Java(TM) SE Runtime Environment (build 1.8.0_161-b12) Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)