Pooling data from server using RMI and springs

Question

I am new to RMI and springs and need a little help with a feature we are implementing.

We are creating chat software with java and want to use RMI with springs. I can setup a client server interaction fairly easily using RMIServerExporter, interfaces, etc.

The problem I can get my head around is that the client needs to pool data from the server. We need to get keep checking for new messages. We can't push data from the server for other reasons.

How do I go about setting up RMI with springs so that the client pools data from the server. I have looked up callbacks but this involved pushing from the server!?

Is there away to do this. Let me know if you need to me explain this further

Answer 1

RMI is just a transport protocol used for client-server communication. On client side, once your RmiProxyFactoryBean has been properly defined and initialized in Spring container, where, when and how to use this service bean is totally up to developer. For a server pooling implementation, we usually use ScheduledThreadPoolExecutor to schedule the RMI call in a given time interval, for example:

public class ChatClient {
  // Defined and wired as RmiProxyFactoryBean in applicationContext.xml
  private ChatService chatService;

  private ScheduledExecutorService scheduleTaskService;

  ... ...

  // At some point during chat application running life cyle:
  scheduleTaskService = Executors.newScheduledThreadPool(5);

  // This schedule pooling task to run every 2 minutes:
  scheduleTaskService.scheduleAtFixedRate(new Runnable() {
    public void run() {
      // Pooling server using RMI call:
      chatService.poolingData();
    }
  }, 0, 2, TimeUnit.MINUTES);

  ... ...

}

For a more enterprise solution, we usually use Quartz, check out this blog post as a live example.