org.springframework.orm.hibernate4.support
Class OpenSessionInViewFilter

java.lang.Object
  extended by org.springframework.web.filter.GenericFilterBean
      extended by org.springframework.web.filter.OncePerRequestFilter
          extended by org.springframework.orm.hibernate4.support.OpenSessionInViewFilter
All Implemented Interfaces:
Filter, Aware, BeanNameAware, DisposableBean, InitializingBean, EnvironmentAware, ServletContextAware

public class OpenSessionInViewFilter
extends OncePerRequestFilter

Servlet 2.3 Filter that binds a Hibernate Session to the thread for the entire processing of the request. Intended for the "Open Session in View" pattern, i.e. to allow for lazy loading in web views despite the original transactions already being completed.

This filter makes Hibernate Sessions available via the current thread, which will be autodetected by transaction managers. It is suitable for service layer transactions via HibernateTransactionManager as well as for non-transactional execution (if configured appropriately).

NOTE: This filter will by default not flush the Hibernate Session, with the flush mode set to FlushMode.NEVER. It assumes to be used in combination with service layer transactions that care for the flushing: The active transaction manager will temporarily change the flush mode to FlushMode.AUTO during a read-write transaction, with the flush mode reset to FlushMode.NEVER at the end of each transaction.

WARNING: Applying this filter to existing logic can cause issues that have not appeared before, through the use of a single Hibernate Session for the processing of an entire request. In particular, the reassociation of persistent objects with a Hibernate Session has to occur at the very beginning of request processing, to avoid clashes with already loaded instances of the same objects.

Looks up the SessionFactory in Spring's root web application context. Supports a "sessionFactoryBeanName" filter init-param in web.xml; the default bean name is "sessionFactory". Looks up the SessionFactory on each request, to avoid initialization order issues (when using ContextLoaderServlet, the root application context will get initialized after this filter).

Since:
3.1
Author:
Juergen Hoeller
See Also:
lookupSessionFactory(javax.servlet.http.HttpServletRequest), OpenSessionInViewInterceptor, HibernateTransactionManager, TransactionSynchronizationManager

Field Summary
static String DEFAULT_SESSION_FACTORY_BEAN_NAME
           
 
Fields inherited from class org.springframework.web.filter.OncePerRequestFilter
ALREADY_FILTERED_SUFFIX
 
Fields inherited from class org.springframework.web.filter.GenericFilterBean
logger
 
Constructor Summary
OpenSessionInViewFilter()
           
 
Method Summary
protected  void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
          Same contract as for doFilter, but guaranteed to be just invoked once per request.
protected  String getSessionFactoryBeanName()
          Return the bean name of the SessionFactory to fetch from Spring's root application context.
protected  SessionFactory lookupSessionFactory()
          Look up the SessionFactory that this filter should use.
protected  SessionFactory lookupSessionFactory(HttpServletRequest request)
          Look up the SessionFactory that this filter should use, taking the current HTTP request as argument.
protected  Session openSession(SessionFactory sessionFactory)
          Open a Session for the SessionFactory that this filter uses.
 void setSessionFactoryBeanName(String sessionFactoryBeanName)
          Set the bean name of the SessionFactory to fetch from Spring's root application context.
 
Methods inherited from class org.springframework.web.filter.OncePerRequestFilter
doFilter, getAlreadyFilteredAttributeName, shouldNotFilter
 
Methods inherited from class org.springframework.web.filter.GenericFilterBean
addRequiredProperty, afterPropertiesSet, destroy, 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 Detail

DEFAULT_SESSION_FACTORY_BEAN_NAME

public static final String DEFAULT_SESSION_FACTORY_BEAN_NAME
See Also:
Constant Field Values
Constructor Detail

OpenSessionInViewFilter

public OpenSessionInViewFilter()
Method Detail

setSessionFactoryBeanName

public void setSessionFactoryBeanName(String sessionFactoryBeanName)
Set the bean name of the SessionFactory to fetch from Spring's root application context. Default is "sessionFactory".

See Also:
DEFAULT_SESSION_FACTORY_BEAN_NAME

getSessionFactoryBeanName

protected String getSessionFactoryBeanName()
Return the bean name of the SessionFactory to fetch from Spring's root application context.


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

Specified by:
doFilterInternal in class OncePerRequestFilter
Throws:
ServletException
IOException

lookupSessionFactory

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

The default implementation delegates to the lookupSessionFactory() variant without arguments.

Parameters:
request - the current request
Returns:
the SessionFactory to use

lookupSessionFactory

protected SessionFactory lookupSessionFactory()
Look up the SessionFactory that this filter should use.

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

Returns:
the SessionFactory to use
See Also:
getSessionFactoryBeanName()

openSession

protected Session openSession(SessionFactory sessionFactory)
                       throws DataAccessResourceFailureException
Open a Session for the SessionFactory that this filter uses.

The default implementation delegates to the SessionFactory.openSession method and sets the Session's flush mode to "MANUAL".

Parameters:
sessionFactory - the SessionFactory that this filter uses
Returns:
the Session to use
Throws:
DataAccessResourceFailureException - if the Session could not be created
See Also:
FlushMode.MANUAL