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

Keep the persistence unit file (Persistence.xml) as it's. You can override the properties in it as follows.

EntityManagerFactory managerFactory = null;
Map persistenceMap = new HashMap();

persistenceMap.put("javax.persistence.jdbc.url", "");
persistenceMap.put("javax.persistence.jdbc.user", "");
persistenceMap.put("javax.persistence.jdbc.password", "");
persistenceMap.put("javax.persistence.jdbc.driver", "");

managerFactory = Persistence.createEntityManagerFactory("", persistenceMap);
manager = managerFactory.createEntityManager();