开发项目的时候 在一个Job中执行了数据库操作, 用的是懒加载,但是如下错误
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: ......., no session or session was closed
项目中使用 hibernate 注解的方式配置懒加载, 不是xml配置文件,
下面列出从网上搜集到的解决方案
1, 报如下错误
org.hibernate.LazyInitializationException: could not initialize proxy - no Session at
解决方法:
在web.xml中,配置springSevlet的位置,使用org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter,代码如下:
<filter>
<filter-name>Spring OpenEntityManagerInViewFilter</filter-name>
<filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>Spring OpenEntityManagerInViewFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
2, 一般是在定时任务quartzJob中,或者Junit测试中使用懒加载出现的错误, 报如下错误
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: ......., no session or session was closed
解决方法:
添加事务配置注解。junit代码如下:
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {
"file:src/main/webapp/WEB-INF/applicationContext.xml",
"file:src/main/webapp/WEB-INF/demo-servlet.xml"})
@Transactional
public class Job {
...
}
3, 还有一种方法说是lazy=false, 我再 OneToMany | ManyToOne 注解中设置fetch=FetchType.EAGER 也不起作用, 不知道用配置文件的行不行