The Spring Stack 2008 – Part1

Spring 2.0 introduced support for various annotations for configuration purposes, such as:

• @Transactional – The @Transactional annotation may be placed before an interface definition, a method on an interface, a class definition, or a public method on a class. However, please note that the mere presence of the @Transactional annotation is not enough to actually turn on the transactional behavior.
• @Required – used to mark a property as being ‘required-to-be-set’ (i.e. an annotated (setter) method of a class must be configured to be dependency injected with a value)
• @PersistenceContext – annotated on EntityManager instances are not thread safe
• @PersistenceUnit – annotated on EntityManagerFactory instances are thread-safe

Thus, to use annotations for the transactions for my purposes, I do the following:

1. Put an tag tx:annotation-driven in the config file (i.e applicationContext.xml)
2. Put @Transactional annotation in the services class implementation that contains operations on the entity manager

Spring 2.5 introduces support for a complete set of configuration annotations:

• @Autowired in combination with support for the JSR-250 annotations @Resource
• @PostConstruct
• @PreDestroy