Where to start to build an application to send/receive XML file from/to XI?

Hello.

I am very new to XI technology.

I have looked various documents to get familiar with the technology and terms related to it.

I am trying to build a stand-alone applcation to send/recevie XML from/to XI. I need some clue where i should start to do. If there is a sample code about how I can connect to XI or way to receive a message, that would be very helpful to me.

Thanks.