EnityManager won't delete records if I put it in a Runnable

Question

I searched for some answer to my question on this site; but failed on every turn. I can delete fine if I don't put this in a ExecutorService, but if I do, it doesn't delete. No error occurs just the records are still in the database. Please advise.

 public void deleteAllTrials(List<Trials>list) { 
      threadList = list;
      ExecutorService executor = Executors.newFixedThreadPool(1);
      executor.execute(new Job1());
      executor.shutdown();

}

 public class Job1 implements Runnable {
        @Override
        public void run() {
            //Session session = (Session) entityManager.getDelegate();
            EntityManagerFactory emf = entityManager.getEntityManagerFactory();
            EntityManager em = emf.createEntityManager();
            System.out.println("Size of threadList" + threadList.size());
            long start = System.currentTimeMillis(); 

            for(int i =0; i<threadList.size(); i++){
                System.out.println("In thread...");

                       Trials mergedEntity = em.merge(threadList.get(i));
                em.remove(mergedEntity);
            }
            //System.out.println("Result list in service:" + list.size());
            //em.close();
            long end = System.currentTimeMillis();
            System.out.println("Threads took this long:" + (end - start));
        }
    }

Answer 1

I found out that EJBs are more powerful than I thought. If you just add @Asynchronus on top of the method you want the application to separate in a backing thread, it will be acting as a separate thread allowing the user to continue doing what he wants to do without waiting on the process to finish.

 @Asynchronous
 public void deleteAllTrials(List<TrialBillet>list) { 
     List<TrialBillet> threadList = new ArrayList<TrialBillet>();
      threadList = list;
      for(int i =0; i<threadList.size(); i++){
         this.delete(threadList.get(i));
      }


 }