solved: Spring + Hibernate used with JPA and EntityManager => HibernateException: collection is not associated with any session

When I started using lazy loading in Spring + Hibernate project, I encounter this error.

What does NOT solve my issue:

• @Transactional annotation
• OpenSessionInViewInterceptor

The error message was:

HTTP ERROR 500

Problem accessing /user/1. Reason:

    Server Error

Caused by:

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.hibernate.HibernateException: collection is not associated with any session
 at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:894)

Solution for Spring with JPA approach and EntityManager, is to use OpenEntityManagerInViewFilter. Register it in web.xml this way: