请手写一个Spring+SpringMVC+Hibernate的dao层代码。（写出他的增删改查即可）

参考解答

@Repository
public class UserDao {

    @Autowired
    private SessionFactory sf;

    public void save(User user) {
        Session session = sf.getCurrentSession();
        session.save(user);
    }

    public void update(User user) {
        Session session = sf.getCurrentSession();
        session.update(user);
    }

    public void delete(int id) {
        Session session = sf.getCurrentSession();
        User user = session.get(User.class, id);
        if(user != null) {
            session.delete(user);
        }
    }

    public User findById(int id) {
        Session session = sf.getCurrentSession();
        return session.get(User.class, id);
    }

    public List<User> findAll(){
        Session session = sf.getCurrentSession();
        Query q = session.createQuery("from User");
        return q.list();        
    }
}