failed to lazily initialize a collection of role

spring mvc 报错：failed to lazily initialize a collection of role

在

web.xml

添加

 <filter>
  <filter-name>openSessionInViewFilter</filter-name>
  <filter-class>org.springframework.orm.hibernate4.support.OpenSessionInViewFilter</filter-class>
  <init-param>
   <param-name>singleSession</param-name>
   <!-- singleSession默认为true,若设为false则等于没用OpenSessionInView -->   
   <param-value>true</param-value>
  </init-param>
 </filter>

无聊么搜

Open Session In View velocity

详细看

http://blog.csdn.net/a154832918/article/details/6832053