Java – dynamic change persistence unit – JPA

persistence. The persistence unit in XML is created during the construction of the application Since I want to change the database URL at run time, is there any way to modify the persistence unit at run time? I should use a different database instead of a pre - bound database

I use eclipse link (JPA 2.1)

Solution

Keep the persistence unit file (persistence. XML) You can override the properties as follows

EntityManagerFactory managerFactory = null;
Map<String,String> persistenceMap = new HashMap<String,String>();

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

managerFactory = Persistence.createEntityManagerFactory("<current persistence unit>",persistenceMap);
manager = managerFactory.createEntityManager();