@EJB private KyrianPagingUtility pagingUtility;
...
javax.persistence.Query qMisEmpresas = entityManager.createQuery(query.toString());
javax.persistence.Query qCountMisEmpresas = entityManager.createQuery(queryCount.toString());

return pagingUtility.getPage(qMisEmpresas, qCountMisEmpresas, new Interval(start,limit));

javax.ejb.EJBException
   at com.sun.ejb.containers.BaseContainer.processSystemException(BaseContainer.java:5119)
   at com.sun.ejb.containers.BaseContainer.completeNewTx(BaseContainer.java:5017)
   at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4805)
   at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2004)
   at com.sun.ejb.containers.EjbAsyncTask.call(EjbAsyncTask.java:110)
   at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
   at java.util.concurrent.FutureTask.run(FutureTask.java:138)
   at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
   at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
   at java.lang.Thread.run(Thread.java:619)
Caused by: javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: could not execute query
   at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1235)
   at org.hibernate.ejb.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1168)
   at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:250)
   at org.hibernate.ejb.criteria.CriteriaQueryCompiler$3.getResultList(CriteriaQueryCompiler.java:260)
   at org.kyrian.dao.util.KyrianPagingUtility.list(KyrianPagingUtility.java:51)
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
   at java.lang.reflect.Method.invoke(Method.java:597)
   at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1056)
   at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1128)
   at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:5292)
   at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:615)
   at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:797)
   at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:567)
   at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doAround(SystemInterceptorProxy.java:157)
   at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:139)
   at sun.reflect.GeneratedMethodAccessor59.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
   at java.lang.reflect.Method.invoke(Method.java:597)
   at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:858)
   at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:797)
   at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:367)
   at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:5264)
   at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:5252)
   at com.sun.ejb.containers.EjbAsyncTask.call(EjbAsyncTask.java:97)
   ... 5 more
Caused by: org.hibernate.exception.GenericJDBCException: could not execute query
   at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
   at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
   at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
   at org.hibernate.loader.Loader.doList(Loader.java:2297)
   at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2172)
   at org.hibernate.loader.Loader.list(Loader.java:2167)
   at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:448)
   at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:363)
   at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
   at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1258)
   at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
   at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:241)
   ... 28 more
Caused by: java.sql.SQLException: Connection closed
   at com.sun.gjc.spi.base.ConnectionHolder.checkValidity(ConnectionHolder.java:703)
   at com.sun.gjc.spi.base.ConnectionHolder.prepareStatement(ConnectionHolder.java:533)
   at com.sun.gjc.spi.jdbc40.ConnectionWrapper40.prepareCachedStatement(ConnectionWrapper40.java:251)
   at com.sun.gjc.spi.jdbc40.ConnectionWrapper40.prepareCachedStatement(ConnectionWrapper40.java:48)
   at com.sun.gjc.spi.ManagedConnection.prepareCachedStatement(ManagedConnection.java:880)
   at com.sun.gjc.spi.jdbc40.ConnectionWrapper40.prepareStatement(ConnectionWrapper40.java:169)
   at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:534)
   at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:452)
   at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
   at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1596)
   at org.hibernate.loader.Loader.doQuery(Loader.java:717)
   at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:270)
   at org.hibernate.loader.Loader.doList(Loader.java:2294)
   ... 36 more

package org.kyrian.dao.util;

import java.io.Serializable;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;

import javax.ejb.AsyncResult;
import javax.ejb.Asynchronous;
import javax.ejb.EJB;
import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.persistence.NoResultException;
import javax.persistence.Query;

import org.kyrian.data.ifc.data.pagination.IPage;
import org.kyrian.utility.util.logs.KyrianLoggerFactory;
import org.slf4j.Logger;






/**
* Session Bean implementation class KyrianPagingUtility
*/
@Stateless
@LocalBean
public class KyrianPagingUtility {
   
   private static final Logger log = KyrianLoggerFactory.getLogger(KyrianPagingUtility.class);
   
   @EJB private KyrianPagingUtility _this;

   /**
    * Devuelve los datos en la ventana
    * especificada por el intervalo
    * @param <T>
    * @param query
    * @param intervalo
    * @return
    */
   @SuppressWarnings("unchecked")
   @Asynchronous
    public <T extends Serializable> Future<List<T>> list(Query query,int start,int results){
      
      query.setFirstResult(start);
      query.setMaxResults(results);
      
      return new AsyncResult<List<T>>(query.getResultList());
             
    }
   
   
   /**
    * Devuelve el número total de los registros en una query
    * @param query
    * @return
    */
   @Asynchronous
   public Future<Long> count(Query query){
      
      Object oTotal = null;
      try{
         oTotal = query.getSingleResult();
      }catch(NoResultException e){
         
      }
      if(oTotal != null){
         Long lTotal = Long.valueOf(((Number) oTotal).longValue());
         return new AsyncResult<Long>(lTotal);
      }
      return new AsyncResult<Long>(0L);
             
    }
   
   
   /**
    *
    * @param <T>
    * @param query
    * @param countQuery
    * @param interval
    * @return
    */
   public <T extends Serializable> IPage<T> getPage(Query query,Query countQuery,Interval interval){
      Future<Long> total = _this.count(countQuery);
      Future<List<T>> listado = _this.list(query, interval.getStart(),interval.getLimit());
         
      DefaultPage<T> page = new DefaultPage<T>();
      try {
         page.setElements(listado.get());
         page.setTotalElements(total.get().intValue());
      } catch (InterruptedException e) {
         log.error("GetPage de forma asíncrona",e);
      } catch (ExecutionException e) {
         log.error("GetPage de forma asíncrona",e);
      }
      
      return page;
   }
}