title: Synchronize access to JPA EntityManager
body: <p>I am using Spring, Hibernate and JPA Entity Manager. When fetching different regions of the UI concurrently (via jquery/ajax) , I would like to synchronise access to JPA Entity Manager, as otherwise it results in shared references to collections exception. How do I achieve this ? I have a controller that calls service methods in the backend which are responsible for calling get/save etc on entitymanager.</p>