Java Database Connectivity (JDBC)

Hi,
I'm developing a distributed system configured as:

- an xml-rpc server that provide/store data into a database
- multiple Swing based client that display/modify the stored data invoking a server remote procedure

so clients don't access the database but simply extract datas from user inputs and send them as parameters of a remote call.
The server (remote) method invoked by clients is declared as syncronized and
I use a single JDBC connection to the database.

I need to give the client the possibility to ask the server to begin a database transaction, to make some (write) request, and finally to commit or rollback depending on requests's success.

Do I have to use JTA API?
Do I have to introduce connection pooling?
And what do you think about this implementation? any suggestion?

Thank's for the attention, sorry for my english