CODEWITHSUNDEEP
sqlitejpaentitymanager
MattC
MattC

Reputation: 6334

Value of closing jpa entitymanager vs. keeping it open

I am running into an issue where if I try to close the entity manager, and then open open it again, my sqlite database is locking:

Caused by: java.sql.SQLException: database is locked
        at org.sqlite.DB.throwex(DB.java:370)
        at org.sqlite.DB.exec(DB.java:76)

But if I just leave the entitymanager open, I don't see the error. So my question is, do I really need to close it? What if this is the only application that will be using this database, does that make a difference in whether or not it needs to be closed?

Here are the 2 methods I created. I was calling initTransaction(), then persisting my objects and committing, and then calling endTransaction(). The error would occur the second time I tried to do this, on tx.commit().

    private EntityManagerFactory emf;
    private EntityManager em;
    private EntityTransaction tx; 

    //in my Java backing bean, multiple methods
        initTransaction();
        em.persist(someObject);
        tx.commit(); //Exception thrown here, but OK first time thru
        endTransaction();        

    private synchronized void initTransaction() {
      if (emf == null || !emf.isOpen()) { emf = Persistence.createEntityManagerFactory("persistenceUnitSqlite"); };   
      if (em == null || !em.isOpen()) { em = emf.createEntityManager(); }
      tx = em.getTransaction();
      if (!tx.isActive()) { tx.begin(); }
    }        

    private synchronized void endTransaction() {
      if (em != null) { em.clear(); em.close(); }
      if (emf != null) { emf.close(); }
      tx = null;
    }

Upvotes: 1

Views: 787

Answers (1)

James
James

Reputation: 18379

Yes, you need to close the EntityManager. The EntityManagerFactory should not normally be closed, it should be held in a static variable as a singleton.

Upvotes: 1

Related Questions