Ok, I figured out that I need to put the class loader into the current thread's context. I am also using an anonymous class loader now, so that only requested classes get loaded (also improves debugging). // check if customizer classes are present and load them final ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader(); final URL customizersUrl = classLoader.findResource("customizers.jar"); if (customizersUrl != null) { ClassLoader cl = new ClassLoader() { @Override public Class loadClass(String className) throws ClassNotFoundException { try { return contextClassLoader.loadClass(className); } catch (ClassNotFoundException ex) { if (customizersUrl != null) { try { URI jarUri = customizersUrl.toURI(); URL[] jarContentUrls = {new URL("jar:file:" + jarUri.getPath() + "!/")}; URLClassLoader customizerInnerClassLoader = URLClassLoader.newInstance(jarContentUrls); return customizerInnerClassLoader.loadClass(className); } catch (URISyntaxException ex1) { logger.debug("Exception during customizer class loading", ex1); } catch (IOException ex1) { logger.debug("Exception during customizer class loading", ex1); } catch (ClassNotFoundException ex1) { throw new ClassNotFoundException("Exception during customizer class loading", ex1); } } } return null; } }; // squeeze our own class loader in Thread.currentThread().setContextClassLoader(cl); } byte[] result = generate(jasperReport, parameters); // changing the class loader back to its origin... just to be safe Thread.currentThread().setContextClassLoader(contextClassLoader);[/code]
