HTTP 状态 500 - 请求处理失败；嵌套异常是 org.hibernate.QueryException：无法解析属性

Question

我是 Spring MVC 和 Hibernate 的新手，我遇到了一个问题。我有 Child table 由 Hibernate 创建，它与用户 table （多对一）连接。当 Hibernate 创建 Child table 时，会自动添加 'user_object_id' - 通过 'user_object' （键入用户）这两个 table 已连接。但是，当我只想向用户显示他的 children 时，出现了问题：

HTTP Status 500 - Request processing failed; nested exception is org.hibernate.QueryException:
could not resolve property: user_object_id of: com.websystique.springmvc.model.Child

我在ChildDaoImpl class的findAllUserChilds方法中从table得到Childobject，然后映射到Child控制器中的 DTO (POJO object)。错误与 Child 模型中的 'user_object_id' 相关，因为该变量在那里不存在，因为它由 Hibernate 自动创建并由 Criteria 在 findAllUserChilds() 中返回。我该如何解决这个问题？

Child:

@Entity
@Table(name= "Child")
public class Child implements Serializable
{ 

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private int id;

@Column (nullable=false)
private String first_name;

@Column (nullable=false)
private String last_name;

@Column (nullable=false)
private String birth_city;

@Column (nullable=false)
private String pesel;

@Column (nullable=false)
private String sex;

@Column (nullable=false)
private String blood_group;

@Column (nullable=false)
private String birth_date;


@ManyToOne
private User user_object;

public User getUser_object() {
    return user_object;
}

public void setUser_object(User user_object) {
    this.user_object = user_object;
}

(... 
some getters and setters
...)

}

Child控制器：

@RequestMapping(value = "/mainpanel" , method = RequestMethod.GET, 
        headers = "accept=application/json")
public List<ChildDTO> listChild(HttpServletResponse request)
{
    Authentication auth =     SecurityContextHolder.getContext().getAuthentication();

    String username = auth.getName();

    User user = userService.findUserByUsername(username);

    List<Child> list = service.findAllUserChilds(user.getId());

    List<ChildDTO> result = new ArrayList<>();

    for (Child child : list)
    {
        result.add(ChildMapper.map(child));
    }

    return result;
}

ChildDaoImpl:

@Repository("ChildDao")
public class ChildDaoImpl extends AbstractDao<Integer, Child> implements     ChildDao {

@SuppressWarnings("unchecked")
public List<Child> findAllUserChilds(int user_id)
{
    Criteria criteria = createEntityCriteria();
    criteria.add(Restrictions.eq("user_object_id", user_id));
    return (List<Child>) criteria.list();
}

}

Answer 1

Child 没有属性 user_object_id 但 user_object。您必须使用 user_object.id（如果 id 是 User 中的属性名称）

HTTP 状态 500 - 请求处理失败；嵌套异常是 org.hibernate.QueryException：无法解析属性

HTTP Status 500 - Request processing failed; nested exception is org.hibernate.QueryException: could not resolve property

java

spring

hibernate

http-status-code-500

HTTP 状态 500 - 请求处理失败；嵌套异常是 org.hibernate.QueryException：无法解析 属性

HTTP Status 500 - Request processing failed; nested exception is org.hibernate.QueryException: could not resolve property

java

spring

hibernate

http-status-code-500

HTTP 状态 500 - 请求处理失败；嵌套异常是 org.hibernate.QueryException：无法解析属性