protected EntityManager createEntityManager(EntityManagerFactory emf) 
{
		return emf.createEntityManager();
}

Create a JPA EntityManager to be bound to a request.

Can be overridden in subclasses.

 protected  void doFilterInternal(HttpServletRequest request,
    HttpServletResponse response,
    FilterChain filterChain) throws ServletException, IOException 
{
		EntityManagerFactory emf = lookupEntityManagerFactory(request);
		boolean participate = false;
		if (TransactionSynchronizationManager.hasResource(emf)) {
			// Do not modify the EntityManager: just set the participate flag.
			participate = true;
		}
		else {
			logger.debug("Opening JPA EntityManager in OpenEntityManagerInViewFilter");
			try {
				EntityManager em = createEntityManager(emf);
				TransactionSynchronizationManager.bindResource(emf, new EntityManagerHolder(em));
			}
			catch (PersistenceException ex) {
				throw new DataAccessResourceFailureException("Could not create JPA EntityManager", ex);
			}
		}
		try {
			filterChain.doFilter(request, response);
		}
		finally {
			if (!participate) {
				EntityManagerHolder emHolder = (EntityManagerHolder)
						TransactionSynchronizationManager.unbindResource(emf);
				logger.debug("Closing JPA EntityManager in OpenEntityManagerInViewFilter");
				EntityManagerFactoryUtils.closeEntityManager(emHolder.getEntityManager());
			}
		}
}

 protected String getEntityManagerFactoryBeanName() 
{
		return this.entityManagerFactoryBeanName;
}

Return the bean name of the EntityManagerFactory to fetch from Spring's root application context.

 protected EntityManagerFactory lookupEntityManagerFactory() 
{
		if (logger.isDebugEnabled()) {
			logger.debug("Using EntityManagerFactory '" + getEntityManagerFactoryBeanName() +
					"' for OpenEntityManagerInViewFilter");
		}
		WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
		return wac.getBean(getEntityManagerFactoryBeanName(), EntityManagerFactory.class);
}

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.

 protected EntityManagerFactory lookupEntityManagerFactory(HttpServletRequest request) 
{
		return lookupEntityManagerFactory();
}

Look up the EntityManagerFactory that this filter should use, taking the current HTTP request as argument.

Default implementation delegates to the lookupEntityManagerFactory without arguments.

 public  void setEntityManagerFactoryBeanName(String entityManagerFactoryBeanName) 
{
		this.entityManagerFactoryBeanName = entityManagerFactoryBeanName;
}

Set the bean name of the EntityManagerFactory to fetch from Spring's root application context. Default is "entityManagerFactory".