In this chapter, we discussed the persistence layer in depth. The discussion gave us an orientation on how to integrate JDBC in an application using Spring via DataSource. However, using JDBC still exposes the developers to JDBC APIs and its operations, such as getting Statement, PreparedStatement, and ResultSet. But JdbcTemplate and JdbcDaoSupport provide a means to perform database operations without getting involved in JDBC APIs. We also saw the exception hierarchy given by Spring, which can be used according to the situation in the application. We discussed Hibernate as an ORM tool, and its integration in the framework. Cache helps in minimum hits to the database, and enhances performance. We will discuss cache managers, and how to integrate CacheManger in the application.

In the next chapter, we will discuss Aspect Oriented Programming, which helps in handling cross-cutting technologies.