Java EE (Java Enterprise Edition) General Discussion

I need your advice regarding common and good practices regarding EJB and JDBC programming.
I write a stateless session bean with bean managed transactions using standard JDBC transactions. So in a method I do following: 1. checkout a database connection from the pooled datasource,
2. do all the needed work in the database (using stored procedures),
3. COMMIT or ROLLBACK the transaction
4. close the database connection to put it back into the pool.

Now the question is whether it is better to pass the connection object to each called class/method, or to use a ThreadLocal singleton to store the Connection object "globally" where it can be retrieved from any method that needs a database connection.
I would use the ConnectionDispenser as described in the article "Threading lightly, Part 3" from Brian Goetz (http://www-106.ibm.com/developerworks/java/library/j- threads3.html).

A further problem is that I want to use SQLJ that retrieves the database connection from a DefaultContext singleton by default. To enable this to work in a EJB environment I have to retrieve a new ConnectionContext from my ConnectionDispenser in each method. If you have better solutions for this, please let me know.

Thanks for your contributions,
Robert