EJB 3 transactions, Java 5 and AspectWerkz AOP.
Step by step tutorial that will guide thru a Java 5 based sample with a quite interesting goal: implement a subset of the EJB 3 specification with AspectWerkz in less than 1 hour 
http://www.theserverside.com/articles/article.tss?l=AspectWerkzP2
Introduction to AOP (spanish).
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