include Java
require "C:/Programming/javalib/h2/bin/h2.jar"

module JavaLang
  include_package 'java.lang'
end

module JavaSql
  include_package 'java.sql'
end

JavaLang::Class.forName("org.h2.Driver")



... and my output...

URLClassLoader.java:200:in `java.net.URLClassLoader$1.run': java.lang.ClassNotFoundException: org.h2.Driver (NativeException)
        from AccessController.java:-2:in `java.security.AccessController.doPrivileged'
        from URLClassLoader.java:188:in `java.net.URLClassLoader.findClass'
        from ClassLoader.java:306:in `java.lang.ClassLoader.loadClass'
        from Launcher.java:276:in `sun.misc.Launcher$AppClassLoader.loadClass'
        from ClassLoader.java:251:in `java.lang.ClassLoader.loadClass'
        from ClassLoader.java:319:in `java.lang.ClassLoader.loadClassInternal'
        from Class.java:-2:in `java.lang.Class.forName0'
        from Class.java:169:in `java.lang.Class.forName'
         ... 18 levels...
        from Main.java:183:in `org.jruby.Main.runInterpreter'
        from Main.java:120:in `org.jruby.Main.run'
        from Main.java:95:in `org.jruby.Main.main'
Complete Java stackTrace
java.lang.ClassNotFoundException: org.h2.Driver
        at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:276)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:169)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.jruby.javasupport.JavaMethod.invokeWithExceptionHandling(JavaMethod.java:196)
        at org.jruby.javasupport.JavaMethod.invoke_static(JavaMethod.java:182)
        at org.jruby.javasupport.JavaClass$StaticMethodInvoker.execute(JavaClass.java:386)
        at org.jruby.internal.runtime.methods.SimpleCallbackMethod.call(SimpleCallbackMethod.java:81)
        at org.jruby.evaluator.EvaluationState.callNode(EvaluationState.java:571)
        at org.jruby.evaluator.EvaluationState.evalInternal(EvaluationState.java:207)
        at org.jruby.evaluator.EvaluationState.blockNode(EvaluationState.java:533)
        at org.jruby.evaluator.EvaluationState.evalInternal(EvaluationState.java:201)
        at org.jruby.evaluator.EvaluationState.rootNode(EvaluationState.java:1614)
        at org.jruby.evaluator.EvaluationState.evalInternal(EvaluationState.java:356)
        at org.jruby.evaluator.EvaluationState.eval(EvaluationState.java:164)
        at org.jruby.Ruby.eval(Ruby.java:278)
        at org.jruby.Ruby.compileOrFallbackAndRun(Ruby.java:306)
        at org.jruby.Main.runInterpreter(Main.java:238)
        at org.jruby.Main.runInterpreter(Main.java:183)
        at org.jruby.Main.run(Main.java:120)
        at org.jruby.Main.main(Main.java:95)