I've setup RMI + SSL. This works great. But it doesn't seem possible to slip compression in between RMI and SSL. So that the RMI requests are compressed before they're sent over SSL.
I've seen some posts online suggest using SSLSocketFactory.createSocket() which takes a Socket to wrap SSL over a compressing socket. But that seems like it would try to compress the SSL protocol itself, which probably isn't very compressable.
I supposed I should create a Socket proxy (subclass of Socket that defers to another Socket, like FilterOutputStream does). Have the proxy wrap the Input/Ouput streams with compression. And have my SocketFactory and ServerSocketFactory return the proxies, wrapping the SSLSocket.
But then we have the buffering issue. Compression buffers the data until it gets enough worth compressing, or is told to flush. This is fine when you don't have back-and-forth communication over the socket. But with cached sockets in RMI, you have that. With no way to identify the end of an RMI request so you can flush your compressed data.
Sun has an RMISocketFactory example doing something like this but they don't address this at all.
notes:
1. SSL supports compression but I can't find anything about enabling that in JSSE
2. I know that compression on lots of small unrelated blocks (as RMI is usually composed of) isn't very beneficial.
3. I know that if I'm sending large requests, RMI isn't the best choice.
4. There is an SSLRMISocketFactory in Java 6. but it doesn't add anything over my custom implementation.