Java TCP Server-Client Design Solution

Question

I'm in the process of developing a highly object-oriented solution, (ie, I want as little coupling as possible, lots of reusability and modular code, good use of design patterns, clean code, etc). I am currently implementing the client-server aspect of the application, and I am new to it. I know how to use Sockets, and how to send streams and receive them. However, I am unsure of actually how to design my solution.

What patterns (if any) are there for TCP Java solutions? I will be sending lots of serialized objects over the network, how do I handle the different requests/objects? In fact, how do I handle a request itself? Do I wrap each object I'm sending inside another object, and then when the object arrives I parse it for a 'command/request', then handle the object contained within accordingly? It is this general design that I am struggling with.

All the tutorials online just seem to be bog-standard, echo servers, that send back the text the client sent. These are only useful when learning about actual sockets, but aren't useful when applying to a real situation. Lots of case statements and if statements just seems poor development. Any ideas? I'd much rather not use a framework at this stage.

Cheers,

Tim.

Answer 1

Consider using a higher level protocol then TCP/IP, don't reinvent the wheel. rmi is a good option and you should be able to find good tutorials on it.

Answer 2

I suggest you either use RMI, or look at it in details so you can determine how you would do things differently. At a minimum I suggest you play with RMI to see how it works before attempting to do it yourself.

Answer 3

If high performance and low latency aren't main requirements then just use existing solutions. And if you decide to use rmi than consider using J2EE with EJB - it'll provide you a transaction management on top of rmi.

Otherwise if you need extremely low latency take a look on sources of existing solutions that use custom protocols on top of tcp. For example OpenChord sends serialized Request and Response objects and Project Voldemort uses custom messages for its few operations.