In this chapter, you learned about ORM and understood the various properties of Hibernate in detail. Then we discussed the important elements of the Hibernate architecture. We have successfully configured Hibernate with the Spring application. We have covered a few pieces of Hibernate functionalities and its features. For better understanding of Hibernate, refer to the Hibernate documentation at http://hibernate.org/.

You also learned how to use HQL and HCQL to query persistent objects. HQL is the most powerful query language to retrieve objects using different conditions. HCQL provides an object-oriented manner to retrieve persistent objects.

In the next chapter, Spring Security, we will first try to understand what Spring Security is. Then, we will look into the dependencies needed for Spring Security. We will take a look at authentication and authorization in Spring Security. We will take a quick review of Servlet filters in web applications and will understand how Spring Security is dependent on this filter mechanism. Afterthat, we will see the two important aspects of Spring Security: the authentication manager and authentication provider.