What's the best way to implement an application server for smartphone app?

I intend to write a multi platform smartphone app (currently only I-phone and android). Which has to send and recieve information from a web server I intend to create. The web server will do all the algorithms, and handles also DB connection. My question, is how is this best accomplished, which kind of web-server technology fit best the scenario, and supports connections from various devices.

Basically, I thought about implementing a simple TCP/IP protocol, making the app (on the phone) the client, and server on the web on the other side. however, I want to deploy the application to an application server (maybe google app, JBOSS, etc.) and I don't want to be stopped by various firewalls.

does anyone has an idea ?

edit: few things are certain, the application server wil开发者_开发百科l be written in java, and db will be mysql.

This is a very broad question and any suggestion about which backend technology to use will depend on your language preferences, your other requirements, etc.

For starters, I'd suggest JSON over HTTP as a transport mechanism: it's easy to parse on both client and server-side, and it's directly usable in Javascript should the need arise. XML is another choice, but it can be annoying to parse.

JSON-over-HTTP (or XML) will be completely device agnostic and won't have the firewall/proxy problems you'll run into trying to do a custom-implemented TCP-based protocol.

For the backend, may folks use MySQL or Postgres for their database, and connect to it from Java, C#, Ruby, PHP, or other server-side languages. Use what you're comfortable with or what you want to learn next.

Why not write the server-side as a regular web application - in whatever technology you like (php, asp.net, java)? This way you can deploy the app on any web server and your client apps on the phones would simply establish a connection to an HTTP server. Normally, firewalls would not be a problem in such situation.

I have used this setup for my apps (both android and iphone) - connecting to a web server app written in php with postgres back-end.