Tudu Lists is a J2EE application for managing todo lists. It's based on Spring 2.5, JPA/Hibernate and AJAX (using the DWR framework). It's a simple yet effective project management tool, and it is also often used as a sample Spring application.
Enable the use of J2EE 5 annotations to configure springframework beans.
Keep all the behavior of a bean within itself, and free the developer from having to look in 3 or 4 diferent files to know what a class really does.