Book Image

Mastering Hibernate

By : Ramin Rad, Koushik Srinivas Kothagal
Book Image

Mastering Hibernate

By: Ramin Rad, Koushik Srinivas Kothagal

Overview of this book

Hibernate has been so successful since its inception that it even influenced the Java Enterprise Edition specification in that the Java Persistence API was dramatically changed to do it the Hibernate way. Hibernate is the tool that solves the complex problem of Object Relational Mapping. It can be used in both Java Enterprise applications as well as .Net applications. Additionally, it can be used for both SQL and NoSQL data stores. Some developers learn the basics of Hibernate and hit the ground quickly. But when demands go beyond the basics, they take a reactive approach instead of learning the fundamentals and core concepts. However, the secret to success for any good developer is knowing and understanding the tools at your disposal. It’s time to learn about your tool to use it better This book first explores the internals of Hibernate by discussing what occurs inside a Hibernate session and how Entities are managed. Then, we cover core topics such as mapping, querying, caching, and we demonstrate how to use a wide range of very useful annotations. Additionally, you will learn how to create event listeners or interceptors utilizing the improved architecture in the latest version of Hibernate.
Table of Contents (16 chapters)

Performance


Performance is a significant architectural concern. We showed how to enable statistics in Hibernate and collect various metrics via JMX in Chapter 7, Metrics and Statistics, to help you identify bottlenecks. Throughout this book, we have identified ways of improving performance. Let's revisit some of these concepts here and discuss how they are effective.

Lazy loading

The decision to use lazy loading depends on specific situations. It is important to understand how lazy loading is accomplished. As we discussed, when you load an entity, Hibernate creates and returns a proxy object, which is uninitialized. (This doesn't occur when you use the get method.) Only when you access one of the attributes of the loaded entity does, Hibernate submit a database query to fetch the values. The same concept applies to associated entities. When you fetch the parent entities, the lazy-loaded associated entities are not fetched until they are accessed. This causes an extra trip to the database....