Class OpenEntityManagerInViewFilter

All Implemented Interfaces:
Filter, Aware, BeanNameAware, DisposableBean, InitializingBean, EnvironmentAware, EnvironmentCapable, ServletContextAware

public class OpenEntityManagerInViewFilter extends OncePerRequestFilter
Servlet Filter that binds a JPA EntityManager to the thread for the entire processing of the request. Intended for the "Open EntityManager in View" pattern, i.e. to allow for lazy loading in web views despite the original transactions already being completed.

This filter makes JPA EntityManagers available via the current thread, which will be autodetected by transaction managers. It is suitable for service layer transactions via JpaTransactionManager or JtaTransactionManager as well as for non-transactional read-only execution.

Looks up the EntityManagerFactory in Spring's root web application context. Supports an "entityManagerFactoryBeanName" filter init-param in web.xml; the default bean name is "entityManagerFactory". As an alternative, the "persistenceUnitName" init-param allows for retrieval by logical unit name (as specified in persistence.xml).

Juergen Hoeller
See Also:
  • Field Details

  • Constructor Details

    • OpenEntityManagerInViewFilter

      public OpenEntityManagerInViewFilter()
  • Method Details

    • setEntityManagerFactoryBeanName

      public void setEntityManagerFactoryBeanName(@Nullable String entityManagerFactoryBeanName)
      Set the bean name of the EntityManagerFactory to fetch from Spring's root application context.

      Default is "entityManagerFactory". Note that this default only applies when no "persistenceUnitName" param has been specified.

      See Also:
    • getEntityManagerFactoryBeanName

      @Nullable protected String getEntityManagerFactoryBeanName()
      Return the bean name of the EntityManagerFactory to fetch from Spring's root application context.
    • setPersistenceUnitName

      public void setPersistenceUnitName(@Nullable String persistenceUnitName)
      Set the name of the persistence unit to access the EntityManagerFactory for.

      This is an alternative to specifying the EntityManagerFactory by bean name, resolving it by its persistence unit name instead. If no bean name and no persistence unit name have been specified, we'll check whether a bean exists for the default bean name "entityManagerFactory"; if not, a default EntityManagerFactory will be retrieved through finding a single unique bean of type EntityManagerFactory.

      See Also:
    • getPersistenceUnitName

      @Nullable protected String getPersistenceUnitName()
      Return the name of the persistence unit to access the EntityManagerFactory for, if any.
    • shouldNotFilterAsyncDispatch

      protected boolean shouldNotFilterAsyncDispatch()
      Returns "false" so that the filter may re-bind the opened EntityManager to each asynchronously dispatched thread and postpone closing it until the very last asynchronous dispatch.
      shouldNotFilterAsyncDispatch in class OncePerRequestFilter
    • shouldNotFilterErrorDispatch

      protected boolean shouldNotFilterErrorDispatch()
      Returns "false" so that the filter may provide an EntityManager to each error dispatches.
      shouldNotFilterErrorDispatch in class OncePerRequestFilter
    • doFilterInternal

      protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException
      Description copied from class: OncePerRequestFilter
      Same contract as for doFilter, but guaranteed to be just invoked once per request within a single request thread. See OncePerRequestFilter.shouldNotFilterAsyncDispatch() for details.

      Provides HttpServletRequest and HttpServletResponse arguments instead of the default ServletRequest and ServletResponse ones.

      Specified by:
      doFilterInternal in class OncePerRequestFilter
    • lookupEntityManagerFactory

      protected EntityManagerFactory lookupEntityManagerFactory(HttpServletRequest request)
      Look up the EntityManagerFactory that this filter should use, taking the current HTTP request as argument.

      The default implementation delegates to the lookupEntityManagerFactory without arguments, caching the EntityManagerFactory reference once obtained.

      the EntityManagerFactory to use
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    • lookupEntityManagerFactory

      protected EntityManagerFactory lookupEntityManagerFactory()
      Look up the EntityManagerFactory that this filter should use.

      The default implementation looks for a bean with the specified name in Spring's root application context.

      the EntityManagerFactory to use
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    • createEntityManager

      protected EntityManager createEntityManager(EntityManagerFactory emf)
      Create a JPA EntityManager to be bound to a request.

      Can be overridden in subclasses.

      emf - the EntityManagerFactory to use
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