package sample.evolve; import javassist.*; /** * DemoLoader is a class loader for running a program including * an updatable class. This simple loader allows only a single * class to be updatable. (Extending it for supporting multiple * updatable classes is easy.) * * To run, type as follows: * * % java sample.evolve.DemoLoader * * Then DemoLoader launches sample.evolve.DemoServer with . * It also translates sample.evolve.WebPage, which sample.evolve.DemoServer * uses, so that it is an updable class. * * Note: JDK 1.2 or later only. */ public class DemoLoader { private static final int initialVersion = 0; private String updatableClassName = null; private CtClass updatableClass = null; /* Creates a DemoLoader for making class WebPage * updatable. Then it runs main() in sample.evolve.DemoServer. */ public static void main(String[] args) throws Throwable { Evolution translator = new Evolution(); ClassPool cp = ClassPool.getDefault(); Loader cl = new Loader(); cl.addTranslator(cp, translator); translator.makeUpdatable("sample.evolve.WebPage"); cl.run("sample.evolve.DemoServer", args); } }