Package org.springframework.orm.jpa.support

Class OpenEntityManagerInViewFilter

java.lang.Object

org.springframework.web.filter.GenericFilterBean

org.springframework.web.filter.OncePerRequestFilter

org.springframework.orm.jpa.support.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).

Since:

2.0

Author:

Juergen Hoeller

See Also:

• OpenEntityManagerInViewInterceptor
• JpaTransactionManager
• SharedEntityManagerCreator
• TransactionSynchronizationManager

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME	Default EntityManagerFactory bean name: "entityManagerFactory".

Fields inherited from class org.springframework.web.filter.OncePerRequestFilter

ALREADY_FILTERED_SUFFIX

Fields inherited from class org.springframework.web.filter.GenericFilterBean

logger

Constructor Summary

Constructors

Constructor	Description
OpenEntityManagerInViewFilter()

Method Summary

Modifier and Type	Method	Description
protected EntityManager	createEntityManager(EntityManagerFactory emf)	Create a JPA EntityManager to be bound to a request.
protected void	doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)	Same contract as for doFilter, but guaranteed to be just invoked once per request within a single request thread.
protected String	getEntityManagerFactoryBeanName()	Return the bean name of the EntityManagerFactory to fetch from Spring's root application context.
protected String	getPersistenceUnitName()	Return the name of the persistence unit to access the EntityManagerFactory for, if any.
protected EntityManagerFactory	lookupEntityManagerFactory()	Look up the EntityManagerFactory that this filter should use.
protected EntityManagerFactory	lookupEntityManagerFactory(HttpServletRequest request)	Look up the EntityManagerFactory that this filter should use, taking the current HTTP request as argument.
void	setEntityManagerFactoryBeanName(String entityManagerFactoryBeanName)	Set the bean name of the EntityManagerFactory to fetch from Spring's root application context.
void	setPersistenceUnitName(String persistenceUnitName)	Set the name of the persistence unit to access the EntityManagerFactory for.
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.
protected boolean	shouldNotFilterErrorDispatch()	Returns "false" so that the filter may provide an EntityManager to each error dispatches.

Methods inherited from class org.springframework.web.filter.OncePerRequestFilter

doFilter, doFilterNestedErrorDispatch, getAlreadyFilteredAttributeName, isAsyncDispatch, isAsyncStarted, shouldNotFilter

Methods inherited from class org.springframework.web.filter.GenericFilterBean

addRequiredProperty, afterPropertiesSet, createEnvironment, destroy, getEnvironment, getFilterConfig, getFilterName, getServletContext, init, initBeanWrapper, initFilterBean, setBeanName, setEnvironment, setServletContext

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME

public static final String DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME

Default EntityManagerFactory bean name: "entityManagerFactory". Only applies when no "persistenceUnitName" param has been specified.

See Also:

• setEntityManagerFactoryBeanName(java.lang.String)
• setPersistenceUnitName(java.lang.String)
• Constant Field Values

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:

• setPersistenceUnitName(java.lang.String)
• DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME

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:

• setEntityManagerFactoryBeanName(java.lang.String)
• DEFAULT_ENTITY_MANAGER_FACTORY_BEAN_NAME

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.

Overrides:

shouldNotFilterAsyncDispatch in class OncePerRequestFilter

shouldNotFilterErrorDispatch

protected boolean shouldNotFilterErrorDispatch()

Returns "false" so that the filter may provide an EntityManager to each error dispatches.

Overrides:

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

Throws:

ServletException

IOException

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.

Returns:

the EntityManagerFactory to use

See Also:

• lookupEntityManagerFactory()

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.

Returns:

the EntityManagerFactory to use

See Also:

• getEntityManagerFactoryBeanName()

createEntityManager

protected EntityManager createEntityManager(EntityManagerFactory emf)

Create a JPA EntityManager to be bound to a request.

Can be overridden in subclasses.

Parameters:

emf - the EntityManagerFactory to use

See Also:

• EntityManagerFactory.createEntityManager()