This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
This is how I would do it: have a base bean that all your services can extend your transaction service so your transactions are at the service level. I'd be interested to see another way of doing this.