When we write down an application, it needs to deal with information and data taken from the real world. Along with processing the accepted data, we also need to use this data for future purposes with the help of the persistence layer. The goal of this chapter was to provide different techniques and ways of storing data permanently. Here we have covered most of the techniques to save the data in database tables using Spring. We've covered JDBC overview, mapping data using Hibernate and the integration of these techniques in Spring. Instead of giving a full stop to development, here we moved a step ahead and carried out JUnit testing to find out how the code is actually behaving for a certain set of data.
In the next chapter, we will learn how to develop the most important layer of an application—the business layer—and about communication between the layers.