Spring + Hibernate + Envers + multithreading - session is closed

Question

We use Hibernate (with JPA) and Hibernate Envers to persist history of objects. The web application runs many threads, some of them are created by RMI method invocation from other applications, some of them are created by the application itself and some of them are created to handle http requests (they generate views). We also use the Open Session In View pattern to manage sessions, so our web.xml contains: ```

openEntityManagerInViewFilter

org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter

openEntityManagerInViewFilter

/*

``` Database is accessed using DAOs, all of them have EntityManagers injected by Spring. ``` @PersistenceContext protected EntityManager em; @PersistenceUnit protected EntityManagerFactory emf; ``` Everything worked quite well before we decided to use Hibernate Envers. When any thread that…

Accepted Answer

We didn't find out why in non-ui threads method calls on `EntityManagerFactory` worked but method calls on `AuditReaderFactory` didn't. Anyway, we found a way to fix it.

The solution was to annotate methods with `@Transactional`. If any method in the call chain before call to the AuditReaderFactory was marked as `@Transactional`, there was no `SessionException` in non-ui threads.

It turned out that making `loadByRevision` transactional was not sufficient. If an object returned by that method contained lazy-loaded persistent bags, access to them outside the `loadByRevision` method scope caused `LazyInitializationException` (there was no session).

The final solution was to make sure that if any thread wants to load some data from the database, all the loading (getting an object and accessing lazy-loaded collections) will be done inside one method annotated with `@Transactional`.

Spring + Hibernate + Envers + multithreading - session is closed

Solution

Problem