User Datastore Interaction

Okay, here's the complete code (in RPXResults.java) for creating users only if they don't already exist:


PersistenceManager pm = PMF.get().getPersistenceManager();

Query query = pm.newQuery("select from omega.server.User where identifier == identifierParam");
query.declareParameters("String identifierParam");

try
{
 List results = (List) query.execute(identifier);

 if (results.size() == 0)
 {
  User user = new User ();
  user.setIdentifier(identifier);
  pm.makePersistent(user);
 }
 else
 {
  User user = results.get(0);
 }
}
finally
{
 query.closeAll();
 pm.close();
}


We could do more about populating User fields from the RPX profile, but this is reasonably complete otherwise. Does this mean the user is logged in?

Unfortunately, no.

By the end of the code, we have loaded the User instance from the datastore (or created it). To get the other pages in the application, and the GWT widgets, to know about the user we have to start a session.

Next post, sessions.