How can I reset/clear the RMIClassLoader

Question

I have a remote method that takes an interface class as an argument. Clients have classes that implement this interface along with serializable. The client has its codebase set to a http://hostname:port/ This works fine, but problems ensue when a client calls this method, exits the application, and then modifies the class file by changing the source code and recompiling. Since the RMIClassLoader keeps track of classes loaded based on the calling process's codebase, it won't reload the class file because a class with that name has already been loaded for that codebase. I've read that the RMIClassLoader can't be cleared, so I'm hoping to find some way to recreate it each time a new client checks in (there is a check-in method that does some setup that all clients call when they start up).
The main goal of this problem is to be able to have an existing RMI server running with new clients connecting in development. The new clients will be using the command pattern to pass intelligient commands to the server via a parameter. Restarting the server every time client code changes is not very efficient.
Thanks
Matt

Answer 1

I don't see how versioning solves this problem.
Let's say the interface contains a method:
public int foo();
and the implemented class overrides this method as follows:
public int foo(){
return 1;
If the client connects to the server, the server will look in the client's codebase to find the class, and will load it (assuming it can get to it).
Now the client disconnects and the programmer decides he really wanted to return 2 and changes his method in his concrete class as follows:
public int foo(){
return 2;
This change will not alter the serialization id.
Now if he starts his application up and connects to the server, the server will check its RMIClassLoader for that codebase and see that it has already encountered that class, deserialize it, and continue to return 1.
If instead the client programmer were to explicitly modify the serialization id of his concrete class and implement the readObject(ObjectInputStream is) and writeObject(ObjectOutputStream os) to handle serialization id discrepancies, the RMIClassLoader is still not going to grab the latest class file and will still return 1.
Am I missing something?