hibernate框架报org.hibernate.LazyInitializationException: could not initialize proxy - no Session

原因：由于lazy懒加载导致，实体对象延迟加载，没有从数据库关联查询出该对象，但是又要获取该对象，所以报错。

解决方法：1.注解修改为  fetch = FetchType.EAGER  急加载

2.想继续使用懒加载，则使用Hibernate.initialize()方法

 

懒加载

改为

懒加载控制台报错情况

严重: Servlet.service() for servlet [springMVC] in context with path [/myserver] threw exception [Request processing failed; nested exception is org.hibernate.LazyInitializationException: could not initialize proxy - no Session] with root cause
org.hibernate.LazyInitializationException: could not initialize proxy - no Session

2.第二种解决方法

想继续使用懒加载，则使用Hibernate.initialize()方法

Hibernate.initialize()；参数为对应字段的获取方法 

以下为实体类外键关联字段，则     Hibernate.initialize(f.getUser_no());

	@ManyToOne(fetch = FetchType.LAZY)
	@JoinColumn(name="user_no")
	private User user_no;

dao层

@Override				//	之前参数	String  user_no
	public List getFriendByUserNo(User user_no) {
		List query=new ArrayList();
		String hql = "from Friend where user_no = ?";
		try {
			query = (List) hibernateTemplate.find(hql, user_no);
			for(Friend f:query)
			{
				Hibernate.initialize(f.getUser_no());
				
			}
			logger.info("--------ByUser_no查询朋友！--------------------");
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
		if (query.size() == 0) {
			return null;
		} else {
			return query;
		}
	}

controller层

		User user=new User();
		user.setNo("212");
		System.out.println(friendService.getFriendByUserNo(user).get(0).getUser_no());