Hibernate中的EntityNotFoundException多对一映射，但存在数据

问题描述

invoice.getUser（）。getId（）

我得到javax.persistence.EntityNotFoundException错误，当我试图通过发票对象获取用户时，

错误如下

：

  javax.persistence.EntityNotFoundException：无法找到com。 （org.hibernate.proxy.AbstractLazyInitializer.checkTargetState（AbstractLazyInitializer.java）：
 org.hibernate.ejb.Ejb3Configuration $ Ejb3EntityNotFoundDelegate.handleEntityNotFound（Ejb3Configuration.java:137）
 org.hibernate.proxy.AbstractLazyInitializer.checkTargetState（AbstractLazyInitializer.java： ）
 at org.hibernate.proxy.AbstractLazyInitializer.getImplementation（AbstractLazyInitializer.java:215）
  





实体类如下（不包括getter和setter）

 @Entity 
 @Table（name =users）
 public class User实现Serializable {
 private s tatic final long serialVersionUID = 1L; 
 
 @Id 
 @GeneratedValue（strategy = GenerationType.AUTO）
 @Column（unique = true，nullable = false）
 private int id; 
 
。 
。 
。 
 
 //双向多对一关联到发票
 @OneToMany（mappedBy =user）
 private List< Invoice>发票; 
 
 $ b $实体
 @Table（name =invoice）
 public class Invoice implements Serializable {
 private static final long serialVersionUID = 1L; 
 
 @Id 
 @GeneratedValue（strategy = GenerationType.AUTO）
 @Column（unique = true，nullable = false）
 private int id; 
。 
。 
。 
 
 //与用户
的双向多对一关联
 @ManyToOne（fetch = FetchType.LAZY）
 @JoinColumn（name =Users_id）
私人用户用户; 
 
  

解决方案

问题可能在于直接实体不存在，但也可能是来自该实体的引用实体，通常为EAGER提取类型，或可选= false。尝试此操作： / p>

  //与用户
的双向多对一关联$ {$ b @ManyToOne（fetch = FetchType.LAZY）
 @JoinColumn（name =Users_id）
 private User user = new User（）; 
  

I am getting javax.persistence.EntityNotFoundException error when I am trying to get User through Invoice object

invoice.getUser().getId()

Error is as follows

javax.persistence.EntityNotFoundException: Unable to find com.indianretailshop.domain.User with id 5
    at org.hibernate.ejb.Ejb3Configuration$Ejb3EntityNotFoundDelegate.handleEntityNotFound(Ejb3Configuration.java:137)
    at org.hibernate.proxy.AbstractLazyInitializer.checkTargetState(AbstractLazyInitializer.java:189)
    at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:178)
    at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:215)

Entity classes are as follows(getters and setters are not included)

@Entity
@Table(name="users")
public class User implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(unique=true, nullable=false)
    private int id;

    .
        .
        .

    //bi-directional many-to-one association to Invoice
    @OneToMany(mappedBy="user")
    private List<Invoice> invoices;
}

@Entity
@Table(name="invoice")
public class Invoice implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(unique=true, nullable=false)
    private int id;
        .
        .
        .

    //bi-directional many-to-one association to User
    @ManyToOne(fetch=FetchType.LAZY)
    @JoinColumn(name="Users_id")
    private User user;
}

解决方案

The problem could be that the direct entity does not exist, but also it could be that the referenced entity from that entity, normally for a EAGER fetch type, or optional=false.

Try this:

     //bi-directional many-to-one association to User
     @ManyToOne(fetch=FetchType.LAZY)
     @JoinColumn(name="Users_id")
     private User user = new User();

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