2 Replies Latest reply on May 20, 2010 8:04 AM by shanika Dias

    Confused with Transaction Management in my Seam application

    shanika Dias Newbie
      Hi,

      I am new to this topic and bit confused as to what strategy exactly i am using since when i read about it there are so many strategies available. And i am not sure if I am using Seam managed transactions. I am using EJB3, seam, JSF with facelets in my application.

      I am injecting my entity manager as  @PersistenceContext (type=EXTENDED) to my stateful session bean. Accoding to documentation that means I am using Container Managed Persistance Context and not Seam Managed PC (since i dond't use @In to inject). Also I dont have any transactions attributes set to either to the class level or to the method level. So i think that means I am using Container Managed Transaction demarcation and expect the container to take care of my transactions. Please correct me if i am wrong.

      So with this, I am trying to see how to rolback the transaction that fails with an Application Exception.  Do i have to call setRollbackOnly method of the EJBContext interface before throwing my Exception? If so how do i get the Context object to call setRollbackOnly method?

      In my example below, i need to do a batch process. Either all objects in the ArrayList must get saved to DB or none if either one failes.

      @Stateful
      @Scope(ScopeType.SESSION)
      @Name("WFMaintenance")
      public class WFMaintenanceBean extends MyBean implements WFMaintenance

        @PersistenceContext (type=EXTENDED) 
          private EntityManager em;

        private ArrayList<Version> selectedVersions = new ArrayList<Version>();

        public void doBatchProcess(){
          try {
           for (Version v : selectedVersions)
               {
                  if (v.getItem() == null){

                     // Should I call setRollbackOnly() here?
                     throw new Exception("Error :Item of this version is null");
                  }
                 
                  // setting new values to v
                  // ....
               
                  em.merge(v);
                  em.flush();
               }

          } catch (Exception e) {     
               // Should I call setRollbackOnly() here as well?          
           e.printStackTrace();
          }

        }


      ...
      }

      Please help me to clarify this.
      Thanks

      Shanika