OpenSessionInViewFilter的两个异常:Illegal attempt to associate a collection with two open sessions

两个常见的异常:Illegal attempt to associate a collection with two open sessions; Write operations are not allowed in read-only mode (FlushMode.NEVER/MANUAL)

使用 Spring 整合 Hibernate, 在懒加载的情况下, 有时候需要在 JSP/View 层显示数据, 这时候就要用到Spring内置的: OpenSessionInViewFilter, 一般来说配置如下(web.xml):

<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>true</param-value>
	</init-param>
	<init-param>
		<param-name>sessionFactoryBeanName</param-name>
		<param-value>sessionFactory</param-value>
	</init-param>
</filter>
<filter-mapping>
	<filter-name>hibernateFilter</filter-name>
	<url-pattern>*.do</url-pattern>
</filter-mapping>

不过, 这时候又会导致更新数据时抛出如下异常:

Write operations are not allowed in read-only mode (FlushMode.NEVER/MANUAL): Turn your Session into FlushMode.COMMIT/AUTO or remove ‘readOnly’ marker from transaction definition.

这时候再去网上找解决方案, 会有人说: 把参数 singleSession改为false, 就行了. 不过, 改完后, 估计不久就会遇到另一个郁闷的异常:

org.hibernate.HibernateException: Illegal attempt to associate a collection with two open sessions

这下完了, 两个方案都不行, 到底怎么办? 还好, 在http://xuliangyong.javaeye.com/blog/144818的主页上, 给了一个方案, 就是改写 OpenSessionInViewFilter 的代码, 非常感谢, 下面给出的就是最终方案:

web.xml

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

< filter-class > org.springframework.orm.hibernate3.support.OurOpenSessionInViewFilter </filter-class>

OurOpenSessionInViewFilter.java 代码:

package org.springframework.orm.hibernate3.support;

import org.hibernate.*;

/** * 单session模式下, 默认会发生无法提交的错误: * Write operations are not allowed in read-only mode (FlushMode.NEVER/MANUAL): Turn your Session into FlushMode.COMMIT/AUTO or remove 'readOnly' marker from transaction definition. * 需要设置FlushMode并刷新session. * 参考: http://xuliangyong.javaeye.com/blog/144818 * @author 刘长炯 */

public class OurOpenSessionInViewFilter extends OpenSessionInViewFilter {

    public OurOpenSessionInViewFilter() {
        super.setFlushMode(FlushMode.AUTO);
    }

    protectedvoid closeSession(Session session, SessionFactory sessionFactory) {
        session.flush();

        try {
            session.getTransaction().commit();
        } catch (HibernateException e) {
            // TODO Auto-generated catch block//e.printStackTrace();
        }

        super.closeSession(session, sessionFactory);
    }
}