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copied!<p>Just rephrasing the question to make sure I it correctly;</p> <p>You want to be able to upload an arbitrary jar file to the server and then use the contained classes/resources in the JVM? Without restarting the JVM and/or editing your configuration ofcourse.</p> <p>If that's the case, then you should load the jar into a classloader (chaining your current classloader if needed) and then load the class from there.</p> <p>Assuming you store the jar-file physically on the server you could for example do something like:</p> <pre><code>public static Class<?> loadClass(String className, String jarFileLocation) throws MalformedURLException, ClassNotFoundException { URL jarUrl = new File(jarFileLocation).toURI().toURL(); ClassLoader classLoader = new URLClassLoader(new URL[] {jarUrl }, MyClass.class.getClassLoader()); return classLoader.loadClass(className); } public static Object executeMethodOndClass(String methodName, Class<?>[] parameterTypes, Object[] parameters, String className, String jarFileLocation) throws MalformedURLException, ClassNotFoundException, IllegalAccessException, InstantiationException, NoSuchMethodException, InvocationTargetException { Class<?> loadedClass = loadClass(className, jarFileLocation); Method method = loadedClass.getMethod(methodName, parameterTypes); Object instance = loadedClass.newInstance(); return method.invoke(instance, parameters); } </code></pre> <p>Ps. this is crude code, I didn't even compile or test it; it <em>should</em> work, but nothing more then that and there is the chance I overlooked something or made a typo ;-)</p> <p>Pps. allowing custom jar files to be uploaded and classes from it to be executed does bring a number of (security) risks with it.</p>

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