Detect RMI client problem. Gotta be anothe way...

Question

For a while, I've been searching how to detect RMI client unexpected disconnection but there is no real answer for that. There is NO other way to let server know that client is disconnected beside using call back or using periodically checking client?? Something like unreferenced() to tell specific client is not holding the reference or something like that..

Answer 1

In our system, almost every Remote interface has a void ping() method, and we periodically call this, and if there is an Exception thrown we do whatever we need to, to clean up.
Often we create a local (static) proxy class to the Remote object that knows how to do the clean up, and has same methods but doesn't throw exceptions. it does NOT implement the Remote interface so there is no need to catch exceptions at every point it is called. This proxy can control the periodic pinging.
I guess you could extend remote and add a ping method to it (call this PingableRemote), then extend this new interface instead of Remote directly.
Also create a class that takes a PingableRemote and some callback object in it's constructor, which could then take care of the pinging and "remoteLost" notification in a form that can be re-used.
Bruce