Re: [eclipselink-users] EntityManager life-cycle..

[Tom Ware <tom.ware@xxxxxxxxxx>]

Hi Paul,

  Can you please provide the rest of the stack trace?  (At least including the 
first line of code that does not belong to EclipseLink)

-Tom

Paul Harrison wrote:
> Hi,
>
> It seems that the recommended pattern is to have a relatively shortly lived EntityManager and use it with the following sort of code
>
>         try {
>             em = getEntityManager();
>             em.getTransaction().begin();
>             //.... do something....
>             em.getTransaction().commit();
>         } finally {
>             if (em != null) {
>                 em.close();
>             }
>         }
>
> where the getEntityManager() call uses a long lived EntityManagerFactory to get new EntityManager. I am having a problem with this pattern in a multi-threaded J2SE environment (specifically Netbeans RCP), where I am getting all sorts of strange exceptions - often  the following
>
> Caused by: java.lang.NullPointerException
>         at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:340)
>         ... 17 more
>
> caused by the class field "processor" being null when two statements earlier it was obviously not null (if in the same thread)
>
> This would tend to suggest that there are threading issues with the EntityManagerFactory/EntityManager that I am not aware of - does anyone have experience of any special tricks necessary to make Eclipselink work properly in Netbeans RCP? I am using Eclipselink 2.2.0 and Netbeans RCP 6.9.1.
>
>
> Paul.
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