title: How do I connect to multiple databases using JPA?
body: <p>I have an application using Java servlets/JSP's. There are multiple clients using my app, however each client has a separate database. All the databases have the same schema. I would like to determine which database connection to use at the time when a user logs into the system. </p>
  
  <p>For example client A logs in, I determine that client A belongs to database C, grab the connection for database C and continue on my merry way.</p>
  
  <p>I am using JPA with Hibernate as my JPA provider. Is it possible to do this using multiple persistence units and determining which unit to use at login time? Is there a better/preferred way to do this?</p>
  
  <p>Edited to add: 
  I am using annotations and EJB's so the Persistence Context is being set in the EJB with @PersistenceContext(unitName = "blahblah"), can this be determined at login time? Can I change the unitName at runtime?</p>
  
  <p>Thanks</p>