How do I insert a lot of entities in a Play! Job?

In my application I have开发者_JS百科 to simulate various situations for analysis. Thus insert a (very) large amount of lines into a database. (We're talking about a very large amount of data...several billion)

Model

@Entity
public class Case extends Model {

    public String url;
}

Job

public class Simulator extends Job {

    public void doJob() {

         for (int i = 0; i !=) {

             // Somestuff

             new Case(someString).save();
         }
    }
}

After half an hour, there is still nothing in the database. But debug traces show Play inserts some stuff. I suspect it is some kind of cache.

I've tried about everything :

Model.em().flush();

Changes nothing.

Model.em().getTransaction().commit();

throws TransactionRequiredException occured : no transaction is in progress

Model.em().setFlushMode(FlushModeType.COMMIT);
Model.em().setFlushMode(FlushModeType.AUTO);

Changes nothing.

I've also tried @NoTransaction annotations everywhere :

• Class & functions in Controller
• Class Case
• Overriding save method in Model
• Class & functions of my Job

Getting quite desperate. Every kind of advice is welcome.

EDIT : After a little research, the first row appears in database. The associated ID is about 550.000. That means about half a million rows are somewhere in between my application and database.

Try

em.getTransaction().begin();
em.persist(model);
em.getTransaction().commit();

You can't commit a transaction before you begin it.

as per documentation, the job should have its own transaction enabled as Play request do, so that's not the issue. Try doing this:

for (int i = 0; i !=) {

  // Somestuff

  Case tmp = new Case(someString);
  tmp = JPA.em().merge(tmp);
  tmp.save();
}

The idea is that you add the newly created object to the EntityManager explicitly before saving, making sure the object is part of the "dirty objects" that will be persisted.

You need to instruct Play! when it should run your job by annotating your class with one of these annotations @OnApplicationStart, @Every or @On.

Please check Play! documentation on jobs