Loading clojure in a custom ClassLoader

[max3000]

Hi,

I want a Java application to support evaluation of older and newer
clojure scripts that may not run on the same clojure versions/
releases. I want to support this without restarting the application.

The approach I'm trying is to load clojure from its own classloader.
My idea is to GC the classloader whenever a clojure version is not
required anymore. Rinse and repeat.

At this point, it doesn't work.

Clojure is NOT in the classpath. I use a custom URLClassLoader which
is given the right clojure path dynamically. However, clojure throws
an Exception because it seems to disregard the classloader it is being
loaded with. Instead, it uses the system class loader (or a child or
the system class loader). Moreover, I can't call RT.addURL because the
exception is thrown from static initializer blocks. The exception is
shown below.


Example code which throws:

// urls contain path to clojure
URLClassLoader classLoader = new URLClassLoader(urls);

// Below: doesn't work
Class.forName("clojure.core__init", true, classLoader);
Class.forName("clojure.lang.RT", true, classLoader);
Class.forName("clojure.lang.Compiler", true, classLoader);

// This works but throws whenever _methClojureLoad is called
clazz = classLoader.loadClass("clojure.lang.Compiler");
_methClojureLoad = clazz.getMethod("load", Reader.class, String.class,
String.class);


Am I wasting my time with this approach? Is there even a way to do
what I want?

Thanks,

Max



Exception in thread "main" java.lang.ExceptionInInitializerError
at clojure.core__init.<clinit>(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at DocumentMgr.loadClojure(DocumentMgr.java:198)
at DocumentMgr.newDocument(DocumentMgr.java:73)
at Application.start(Application.java:105)
at Application.main(Application.java:41)
Caused by: java.lang.RuntimeException: java.io.FileNotFoundException:
Could not locate clojure/core__init.class or clojure/core.clj on
classpath:
at clojure.lang.RT.<clinit>(RT.java:290)
... 7 more
Caused by: java.io.FileNotFoundException: Could not locate clojure/
core__init.class or clojure/core.clj on classpath:
at clojure.lang.RT.load(RT.java:409)
at clojure.lang.RT.load(RT.java:376)
at clojure.lang.RT.doInit(RT.java:413)
at clojure.lang.RT.<clinit>(RT.java:286)
... 7 more