Hands-On High Performance with Spring 5

The open session in view anti-pattern

We saw in the preceding section that in order to defer fetching until the associated entity is needed, we set the fetch type of the associated entities as LAZY. When we try to access these associated entities in our presentation layer (if they are not initialized in our business (service) layer), an exception is thrown by Hibernate, called LazyInitializationException. When the service layer method completes its execution, Hibernate commits the transaction and closes the session. So, by the time the view is rendered, the active session is not available to fetch the associated entities.

To avoid LazyInitializationException, one of the solutions is an open session in view. This means that we keep the Hibernate ...