failed to lazily initialize a collection of role: no session or session was clos

还是做Many-to-One的时候遇见的错误，级联检索不允许。 

试验了一下发现了几个解决方法： 
1、是把对应一对多的那两个列lazy=true改为lazy＝false即可 
2、对于查询中如果用的是xxx.load（class，id）则改为xxx,get(class，id) 
3在web.xml文件中加入 

<filter> 
  <filter-name>hibernateFilter</filter-name> 
  <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class> 

  <init-param> 
            <param-name>singleSession</param-name> 
            <param-value>false</param-value> 
        </init-param> 

<!--这个--  <init-param>一定要加不然很可能会报错：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 
> 
</filter> 

<filter-mapping> 
  <filter-name>hibernateFilter</filter-name> 
  <url-pattern>*.mmg</url-pattern> 
</filter-mapping>