Chapter 4. Relationships, JPA, and advanced persistence


This chapter covers
  • Object relations
  • Defining entity relationships
  • Reverse engineering JPA entities
  • Adding a service layer
  • Using JPA directly
  • NoSQL databases with MongoDB


In chapter 3, we discussed how to install Roo’s JPA-based persistence engine, create entities, and manipulate them using Roo’s domain-driven entity ITD methods such as persist(), find(), and merge(). You saw how to validate entities using the Bean Validation API and how to generate search queries using the finder facility. You also saw how to build Spring-based repositories so that developers who want a separation of application layers can still provide a data layer for their applications.

In this chapter, you’ll ...

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