[jboss-user] [Javassist] - Adding interface to an existing class

[mnrz]

mnrz [http://community.jboss.org/people/mnrz] created the discussion

"Adding interface to an existing class"

To view the discussion, visit: http://community.jboss.org/message/608679#608679

--------------------------------------------------------------
Hi 

I have a class which is in legacy system and we cannot change the class. I need to create a java proxy for that class but this is a class without interface. So I have created an interface and write the following code to add this interface to that class at runtime but the class.getInterfaces() method still returns no interface!

--
public class Main {



    public static void main(String[] args) throws Exception {
        //@SuppressWarnings("rawtypes")
        createInterface();
        AnAbstractClass instance = new AClassFromAbstract();//instance.getClass().getInterfaces()
        Object proxy = Proxy.newProxyInstance(ProxyIntAnAbstractClass.class.getClassLoader(), 
                new Class[] {ProxyIntAnAbstractClass.class},
                new MyInvocationHandler(instance));

        ProxyIntAnAbstractClass instance2 = (ProxyIntAnAbstractClass) proxy;
        instance2.doSomething();
        instance2.doSomethingElse();
    }

    public static Class createInterface() throws Exception{
        ClassPool pool = ClassPool.getDefault();
        ClassPath cp = new ClassClassPath(AnAbstractClass.class);
        pool.insertClassPath(cp);
        pool.importPackage("com.macquarie.test.proxy");

        CtClass myinterface = pool.get("com.mmm.test.proxy.ProxyIntAnAbstractClass");


        CtClass tclass = pool.getCtClass("com.mmm.test.proxy.AnAbstractClass");
        tclass.setInterfaces(new CtClass[] {myinterface});
        tclass.rebuildClassFile();
        tclass.detach();
        return myinterface.toClass();


    }
}

--

When I execute this code, since the ProxyIntAnAbstractClass is not interface of AnAbstractClass, InvocationHandler complains that the object is not an instance of declaring class

Can you please help me on this?
--------------------------------------------------------------

Reply to this message by going to Community
[http://community.jboss.org/message/608679#608679]

Start a new discussion in Javassist at Community
[http://community.jboss.org/choose-container!input.jspa?contentType=1&containerType=14&container=2062]

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/jboss-user/attachments/20110606/c5dfa734/attachment.html