rmi callback gotchas?

What do I need to worry about when doing callbacks in RMI? I just need a simple client notification mechanism to avoid excessive polling.

I found an online example and it looks pretty straightforward, the client just implements an interface that extends Remote (like the server doe开发者_如何学Cs) and passes it to the server, which can then call back its methods. I'm guessing the remote callback can occur on any thread, so I have to assume it will be asynchronous to my client application's normal threads. What else is there?

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Two things.

1. RMI callbacks almost certainly won't work through firewalls

2. RMI callbacks execute on a different thread from the original client call to the server. You can get unexpected synchronization deadlocks if you don't take that into account.