org.hibernate.MappingException：无法确定类型：

Question

我在休眠中映射属性时遇到问题。我只想将 Device（1 对多）映射到 DeviceData（多对 1），反之亦然。我的输出应该是：表：device=id，device（一个设备号），表：DeviceData = id, device_id (forgein key), ...一切都由 json2ojo 生成器生成。@Entity(name = "Device")@Table(name = "device_devices")public class Device {        @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    @JsonProperty    private Long id;    @JsonProperty("device")    @Column(unique = true)    private String device;    @JsonIgnore    private Map<String, Object> additionalProperties = new HashMap<String, Object>();    @OneToMany(fetch = FetchType.LAZY, mappedBy = "device", cascade = CascadeType.ALL, orphanRemoval = true, targetEntity = DeviceData.class)    private List<DeviceData> deviceData = new ArrayList<>();...}@Entity(name = "DeviceData")@Table(name = "device_data")public class DeviceData {    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    @JsonProperty    private Long id;...    @JsonIgnore    @ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY, targetEntity = Device.class)    @JoinColumn(name = "device_id", referencedColumnName = "id")    private Device device;    @JsonIgnore    private Map<String, Object> additionalProperties = new HashMap<String, Object>();   @JsonProperty("id")    public Long getId(){        return id;    }    @JsonIgnore    public Device getDevice(){        return device;    }    @JsonIgnore    public void setDevice(Device device){        this.device = device;    }......    @JsonAnyGetter    public Map<String, Object> getAdditionalProperties() {        return this.additionalProperties;    }    @JsonAnySetter    public void setAdditionalProperty(String name, Object value) {        this.additionalProperties.put(name, value);    }}

Answer 1

默认情况下，JPA 会尝试保留类的所有属性，但您可以使用注释@Entity忽略某些属性。@Transient在您的情况下，如果您不想additionalProperties在两个类中都保留字段，则应将它们标记为@Transient：

@JsonIgnore

@Transient

private Map<String, Object> additionalProperties = new HashMap<String, Object>();