12 Making JPA Entities and JAXB Beans Extensible

This chapter provides instructions for making JPA entities and JAXB beans extensible. Mappings can be added or modified externally, without modifying the entity or bean source file and without redeploying the persistence unit. This feature is useful in a Software-as-a-Service environment where multiple clients can share applications and datasources. It is also useful for customizing an application during installation rather than during development.

This chapter includes the following sections:

• Making JPA Entities Extensible

• Making JAXB Beans Extensible

• Additional Resources

Use Case

Users want to establish a SaaS environment, where applications and datasources are shared by multiple clients.

Solution

Use the EclipseLink extensibility feature to extend JPA entities and JAXB beans by using external mappings.

Components

• EclipseLink 2.4 or later.