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