为什么spring jpa没有会话异常错误

Question

我使用springboot和spring jpa作为我的后端框架。在访问jpa存储库中的实体时，我遇到了以下异常。

    2016-08-16 20:39:27.528 ERROR 19243 --- [http-nio-8090-exec-8] [.[.[.[.c.c.Go2NurseJerseyConfiguration] : Servlet.service() for servlet [com.cooltoo.config.Go2NurseJerseyConfiguration] in context with path [] threw exception [org.hibernate.LazyInitializationException: could not initialize proxy - no Session] with root cause

org.hibernate.LazyInitializationException: could not initialize proxy - no Session
    at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:165) ~[hibernate-core-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:286) ~[hibernate-core-4.3.11.Final.jar!/:4.3.11.Final]
    at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:185) ~[hibernate-core-4.3.11.Final.jar!/:4.3.11.Final]
    at com.cooltoo.go2nurse.entities.UserEntity_$$_jvst80d_8.getPassword(UserEntity_$$_jvst80d_8.java) ~[com.cooltoo.go2nurse-common-1.0.0-SNAPSHOT.jar!/:na]

@Transactional
private UserBean registerWithChannel(String name, int gender, String strBirthday, String mobile, String password, String smsCode, String channel, String channelid) {
       currentUser = repository.findByMobile(mobile);
        //already existed such user, link with channel user
       UserBean userBean = updatePassword(currentUser.getId(), currentUser.getPassword(), password);
       loginService.login(mobile, password);

} 

@Transactional
public UserBean updatePassword(long userId, String oldPassword, String newPassword) {
        logger.info("modify the password by userId={} oldPwd={} newPwd={}",
                userId, oldPassword, newPassword);

        UserEntity user = repository.getOne(userId);
        if (null==user) {
            throw new BadRequestException(ErrorCode.RECORD_NOT_EXIST);
        }

        boolean changed = false;

        // check password
        if (user.getPassword().equals(oldPassword)) { //the exception happens here

        }
        ...
    }

@Transactional注释有什么问题吗？还是因为我在两个方法中使用了相同的UserEntity？

Answer 1

将类标记为@Transactional，那么Spring将处理会话管理而不是方法。@Transactional public class My class{...}通过使用@Transactional,可以自动处理事务传播等许多重要方面。在这种情况下，如果调用另一个事务性方法，则该方法可以选择加入正在进行的事务，从而避免“无会话”异常。

也可以使用传播