URL access to nested .jar files

Tonight I implemented loading of classes from nested jar files. It seems to me that people might be interested in such trick, so here you are.

I created new protocol handler jarjar: which just redirects inner part of URL to .jar handler again. Please note that I use '^/' as jar-in-jar separator to avoid conflict with regular jar handler.

Let's have Outer.jar which contains Inner.jar which contains tested/robots/Ahead.class
Now you can do this

// initialize, just once per JVM please
JarJarURLConnection.register();

new URL(
"jar:jarjar:file:/C:/mylibs/Outer.jar^/Inner.jar!/tested/robots/Ahead.class"
).openStream();

Or create and configure ClassLoader this way

// initialize, just once per JVM please
JarJarURLConnection.register();

new URLClassLoader(
  new URL[]{new URL("jar:jarjar:file:/C:/mylibs/Outer.jar^/Inner.jar!/")}
).loadClass("tested.robots.Ahead");

If you need something more sophisticated or user friendly One-JAR is the solution I think.