Question

当我执行插入操作时，traduction中的外键（idMot引用mot）为null，这是因为当我前台发送正确的外键时。我最终遇到此错误： not-null属性引用的是空值或瞬态值：com.virtual.expertise.mydico.model.Traduction.mot

我想我的模型做错了，但还是不知道什么。

以下是交易模型：

      @Id
            @Column(name = "id")
            @GeneratedValue(strategy = GenerationType.IDENTITY)
            private Long id;

            @Column(name = "langue")
            private String langue;

            @Column(name = "traduction")
            private String traduction;

            @JsonBackReference(value = "mot-traduction")
            @ManyToOne(fetch = FetchType.EAGER)
            @JoinColumn(name = "idMot", nullable = false, insertable = true, 


updatable = false)
        private Mot mot;

        @CreationTimestamp
        @Column(name = "dateCreation")
        private Date dateCreation;

这是mot模型：

@Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "libelle")
    private String libelle;

    @JsonBackReference(value = "user-mot")
    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "idUser", nullable = false, insertable = true, updatable = false)
    private User user;

    /** les traductions. */
    @JsonManagedReference(value = "mot-traduction")
    @OneToMany(mappedBy = "mot", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    private Set<Traduction> traductions;

    @CreationTimestamp
    @Column(name = "dateCreation")
    private Date dateCreation;

以下是交易表格：

DROP TABLE IF EXISTS `traduction`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `traduction` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `langue` varchar(100) DEFAULT NULL,
  `traduction` varchar(100) DEFAULT NULL,
  `idMot` bigint(20) DEFAULT NULL,
  `dateCreation` datetime DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `idMot_idx` (`idMot`),
  CONSTRAINT `idMot` FOREIGN KEY (`idMot`) REFERENCES `mot` (`id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = @saved_cs_client */;

这是我的web服务：（在此过程中，idMot显示为空）

@POST
    @Path("/create")
    public Traduction createTraduction(Traduction traduction) throws Exception {
        return FacadeBackOffice.getInstance().getTraductionService().createTraduction(traduction);
    }

有人可以解决吗？

Answer 1

在多对一映射中也全部使用级联类型。

 @Id
            @Column(name = "id")
            @GeneratedValue(strategy = GenerationType.IDENTITY)
            private Long id;

            @Column(name = "langue")
            private String langue;

            @Column(name = "traduction")
            private String traduction;

            @JsonBackReference(value = "mot-traduction")
            @ManyToOne(fetch = FetchType.EAGER, cascade=CascadeType.ALL)
            @JoinColumn(name = "idMot", nullable = false, insertable = true, 


updatable = false)
        private Mot mot;

        @CreationTimestamp
        @Column(name = "dateCreation")
        private Date dateCreation;

休眠-尝试插入时为空外键

1 个答案: