OpenSessionInViewInterceptor配置

    

    
<beans> 
    
    

    
  <bean name="openSessionInViewInterceptor" 
    
    

    
class="org.springframework.orm.hibernate3.support.OpenSessionInViewInterceptor"> 
    
    

    
    <property name="sessionFactory">
    
    

    
      <ref bean="sessionFactory"/>
    
    

    
    </property> 
    
    

    
  </bean> 
    
    

    
  <bean id="urlMapping" 
    
    

    
class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> 
    
    

    
    <property name="interceptors"> 
    
    

    
      <list> 
    
    

    
        <ref bean="openSessionInViewInterceptor"/> 
    
    

    
      </list> 
    
    

    
    </property> 
    
    

    
    <property name="mappings"> 
    
    

    
    ... 
    
    

    
    </property> 
    
    

    
  </bean> 
    
    

    
... 
    
    

    
</beans> 
    

OpenSessionInViewFilter配置

    

    
<web-app> 
    
    

    
... 
    
    

    
  <filter> 
    
    

    
    <filter-name>hibernateFilter</filter-name> 
    
    

    
    <filter-class> 
    
    

    
      org.springframework.orm.hibernate3.support.OpenSessionInViewFilter 
    
    

    
    </filter-class> 
    
    

    
    <!-- singleSession默认为true,若设为false则等于没用OpenSessionInView -->
    
    

    
    <init-param> 
    
    

    
      <param-name>singleSession</param-name> 
    
    

    
      <param-value>true</param-value>
    
    

    
    </init-param>
    
    

    
  </filter> 
    
    

    
... 
    
    

    
  <filter-mapping> 
    
    

    
    <filter-name>hibernateFilter</filter-name> 
    
    

    
    <url-pattern>*.do</url-pattern> 
    
    

    
  </filter-mapping> 
    
    

    
... 
    
    

    
</web-app> 
    

很多人在使用OpenSessionInView过程中提及一个错误：

    

    
org.springframework.dao.InvalidDataAccessApiUsageException: Write operations 
    
    

    
are not allowed in read-only mode (FlushMode.NEVER) - turn your Session into 
    
    

    
FlushMode.AUTO or remove 'readOnly' marker from transaction definition 
    

看看OpenSessionInViewFilter里的几个方法

    

    
protected void doFilterInternal(HttpServletRequest request, 

    HttpServletResponse response,FilterChain filterChain) 

    throws ServletException, IOException {

    　SessionFactory sessionFactory = lookupSessionFactory();

    logger.debug("Opening Hibernate Session in OpenSessionInViewFilter");

    Session session = getSession(sessionFactory);

    TransactionSynchronizationManager.bindResource(

    　　sessionFactory, new SessionHolder(session));

    try {

    　　filterChain.doFilter(request, response);

    }

    　finally {

    　TransactionSynchronizationManager.unbindResource(sessionFactory);

    logger.debug("Closing Hibernate Session in OpenSessionInViewFilter");

    closeSession(session, sessionFactory);

    }

    }

    

    

    

    

     
    
    

    
protected Session getSession(SessionFactory sessionFactory)

    throws DataAccessResourceFailureException {

    　Session session = SessionFactoryUtils.getSession(sessionFactory, true);

    session.setFlushMode(FlushMode.NEVER);

    return session;

    }
    
    


    protected void closeSession(Session session, SessionFactory sessionFactory)

    throws CleanupFailureDataAccessException {

    　SessionFactoryUtils.closeSessionIfNecessary(session, sessionFactory);

    } 

     可以看到OpenSessionInViewFilter在getSession的时候,会把获取回来的session的flush mode 设为FlushMode.NEVER。然后把该sessionFactory绑定到 TransactionSynchronizationManager，使request的整个过程都使用同一个session，在请求过后再接除该 sessionFactory的绑定，最后closeSessionIfNecessary根据该 session是否已和transaction绑定来决定是否关闭session。在这个过程中，若HibernateTemplate 发现自当前session有不是readOnly的transaction，就会获取到FlushMode.AUTO Session，使方法拥有写权限。

    

    
public static void closeSessionIfNecessary(Session session, SessionFactory sessionFactory)
    
    

    
      throws CleanupFailureDataAccessException {
    
    

    
    if (session == null || 

    TransactionSynchronizationManager.hasResource(sessionFactory)) {
    
    

    
      return;
    
    

    
    }
    
    

    
    logger.debug("Closing Hibernate session");
    
    

    
    try {
    
    

    
      session.close();
    
    

    
    }
    
    

    
    catch (JDBCException ex) {
    
    

    
      // SQLException underneath
    
    

    
      throw new CleanupFailureDataAccessException("Could not close Hibernate session", ex.getSQLException());
    
    

    
    }
    
    

    
    catch (HibernateException ex) {
    
    

    
      throw new CleanupFailureDataAccessException("Could not close Hibernate session", ex);
    
    

    
    }
    
    

    
  } 
    

    也即是，如果有不是readOnly的transaction就可以由Flush.NEVER转为Flush.AUTO,拥有insert, update,delete操作权限，如果没有transaction，并且没有另外人为地设flush model的话，则doFilter的整个过程都是Flush.NEVER。所以受transaction保护的方法有写权限，没受保护的则没有。

采用spring的事务声明,使方法受transaction控制

    

    
  <bean id="baseTransaction" 

    class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean" 

              abstract="true"> 

            <property name="transactionManager" ref="transactionManager"/> 

            <property name="proxyTargetClass" value="true"/> 

            <property name="transactionAttributes"> 

                <props> 

                    <prop key="get*">PROPAGATION_REQUIRED,readOnly</prop> 

                    <prop key="find*">PROPAGATION_REQUIRED,readOnly</prop> 

                    <prop key="load*">PROPAGATION_REQUIRED,readOnly</prop> 

                    <prop key="save*">PROPAGATION_REQUIRED</prop> 

                    <prop key="add*">PROPAGATION_REQUIRED</prop> 

                    <prop key="update*">PROPAGATION_REQUIRED</prop> 

                    <prop key="remove*">PROPAGATION_REQUIRED</prop> 

                </props> 

            </property> 

        </bean> 

    
    
    
    <bean id="userService" parent="baseTransaction"> 

            <property name="target"> 

                <bean class="com.phopesoft.security.service.impl.UserServiceImpl"/> 

            </property> 

        </bean>