Question

I’m sure this seems obvious to most java programmers — and I “think” I know the answer, but my issue is that I need to use a custom class loader. I’d like to use the custom class loader and still be able to use the classes in my code as I would any included class.

Example:

// returns my class loader -- set earlier on the thread.
ClassLoader cl = Thread.currentThread().getContextClassLoader();
Class loadedVersion = Class.forName("org.example.MyClass"); // works
// loadedVersion's class loader is also equal to cl

// generates "java.lang.NoClassDefFoundError" at runtime on the following line
org.example.MyClass m = new org.example.MyClass();

How would I go about doing this so I can have the class loaded using the custom class loader, and still be able to use my classes “plainly” in the editor?

Edit: The revised title is misleading — the classes load just fine. As indicated in my original post. The issue, my understanding, is that I am currently unable to use the classes in regular declaration statements (in the editor as I would use any java.* classes).

Update, I hope this better explains what I’m trying to do.

// set the thread's class loader
ClassLoader cloader = new MyClassLoader(); // internal mess to load bytecode omitted
Thread.currentThread().setContextClassLoader(cloader);

// This works:
Method m = cloader.loadClass("my.SuperClass").getMethod("doStaticMagic", new Class<?>[] {});
m.invoke(null, null);

// This does not work:
my.SuperClass.doStaticMagic(); // NoClassDefFoundError

This is the “issue”. I want to use my classes “plainly” (I really don’t know the right word) in the editor. I don’t want to have to load each individual method — isn’t that what the classloader is for?

Answer 1

Here is my solution (answer) to my original question. I still don’t consider this ideal, but this does work.

I created a “bootstrap” application that first loads all the custom 3rd party jars, and then loads and calls my application class. This way I get auto-complete and source hints for the 3rd party jars.

I hope this helps someone, or invites further comments.