Network communication options in Java (Client/Server)

There is RMI, which I understand to be relatively fragile, direct Socket connections, which is rather low level, and Strings, which while about as solid as it gets seems to be the metapho开发者_如何学JAVArical PHP.

What less basic options do I have for internet based Client/Server communication ? What are the advantages/disadvantages ? What are some concerns I should take into consideration ? Third party library suggestions are fine, as long as they stay platform independent (i.e. no restrictive native code).

Looking for options, not a definite answer, so I'm leaving the details of my own requirements blank.

As you specified "internet based", there's a lot to be said for an HTTP-based, RESTful approach (I've highlighted some concerns you should consider):

Pros:

• You can use/abuse one of the myriad web-tier frameworks for the server side (e.g. Spring MVC, Play!)
• The low-level work has been done on client-side (Apache HTTPClient)
• Plain-text protocol is easy to debug on the wire
• Tons of tools available to help you debug the interactions (e.g. SoapUI) - you can pretend to be client OR server and so develop in isolation until the other end is ready
• Using a well-known port (80/443) makes punching through corporate firewalls a whole lot easier

Cons:

• There's a fairly major assumption that the server will be doing the lion's share of the work - if your model is "inverted" then it might not make much sense to be RESTful
• Raw performance will be lower than a bits-on-the-wire socket-based approach
• Plain-text protocol is easy to sniff on the wire (SSL can remedy this)

What does 'relatively fragile' mean? The issues with RMI have to do with it being a large superstructure on a narrow foundation, and specifically that it has a large reliance on DNS and Object Serialization. The closer you are to the silicon, the less 'fragile' any program becomes, but the more code you have to write. It's a tradeoff. I'm not a one-eyed RMI supporter, despite having written a book about it, but 'fragility' is too strong a word. It does what it does, and it does that reasonably well. RMI/IIOP does it even better in many respects if you need large-scale scalability. If your view of the world is an at-most-once remote method call without too much security, RMI/JRMP will give it to you. The further you get from that model the harder it becomes to apply.