Changing Persistence Unit dynamically - JPA

Question

Persistence units in persistence.xml are created during building the application. As I want to change the database url at runtime, is there any way to modify the persistence

Answer 1

In Long-lived Session Architecture you should create a Plug-in-Framework.

Therefore you need to create a different Thread-Group and Class-Repository.

This might be your Class-Loader-Tree

• System-Class-Loader (usually a URLClassLoader, contains the Entitys)
  • JPA-Class-Loader
    • Load your jpa.jar with persistence.xml inside, specify the Database-Configuration from Application-Class-Loader
    • Instanciate your entityManager/session-factory.
    • Load any plugin you need to work with the DataBase. Execute Unit-Tests (;D) and Plugin-Integration-Tests.