In the previous chapters, you saw how easy it is to build a fully Spring-managed application. You now have a solid understanding of bean configuration and Aspect-Oriented Programming (AOP)—in other words, you know how to wire up the entire application using Spring. However, one of the parts of the puzzle is missing: how do you get the data that drives the application?
Apart from simple throwaway command-line utilities, almost every application needs to persist data to some kind of data store. The most usual and convenient data store is a relational database.