Chapter 19Introducing Java Persistence API and Hibernate ORM

  • Understanding data persistence
  • What is an Object-Relational Mapper?
  • Understanding Hibernate ORM
  • How to prepare a relational database
  • How to use the Maven dependencies in this Part

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NEW MAVEN DEPENDENCIES FOR THIS CHAPTER

There are no new Maven dependencies for this chapter. Continue to use the Maven dependencies introduced in all previous chapters.

WHAT IS DATA PERSISTENCE?

With few exceptions, every application needs persistence in some form or another. But what exactly is persistence? Put simply, persistence is making some form of data last across multiple executions of an application. In that sense, logging is a form of persistence because it persists diagnostic information about program execution so that you can analyze it while or after the application executes. Indeed, you can persist logging information to a flat file, an XML file, a JSON file, a database, or any number of other media, as is the case with all other forms of persistence.

Generally, however, persistence does not refer to logging. Instead, it refers to the saving of entities within the application to some storage media. Entities can be anything — people, users, tickets, forum posts, shopping carts, store orders, products, news articles, and more. The list goes on, and this entire book is not long enough to enumerate them all. In software development, ...

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