Question

例如，我从外部供应商（其中Page_Load可以是变量）接收此JSON：

payload

我正在尝试使用此类对它们进行建模：

{
  "payload": {
    "enrolledAt": "2018-11-05T00:00:00-05:00",
    "userId": "99c7ff5c-2c4e-423f-abeb-2e5f3709a42a"
  },
  "requestId": "80517bb8-2a95-4f15-9a73-fcf3752a1147",
  "eventType": "event.success",
  "createdAt": "2018-11-05T16:55:13.762-05:00"
}

...然后具有以下可能的（通用）类型：

public final class Notification<T extends AbstractModel> {
  @JsonProperty("requestId")
  private String requestId;

  @JsonProperty("eventType")
  private String eventType;

  @JsonProperty("createdAt")
  private ZonedDateTime createdAt;

  private T payload;

  @JsonCreator
  public Notification(@JsonProperty("payload") T payload) {
    requestId = UUID.randomUUID().toString();
    eventType = payload.getType();
    createdAt = ZonedDateTime.now();
    this.payload = payload;
  }

  // getters
}

public abstract class AbstractModel {
  private String userId;

  private Type type;

  @JsonCreator
  AbstractModel(@JsonProperty("companyUserId") String userId, @JsonProperty("type") Type type) {
    this.userId = userId;
    this.type = type;
  }

  // getters

  public enum Type {
    CANCEL("event.cancel"),
    SUCCESS("event.success");

    private final String value;

    Type(String value) {
      this.value = value;
    }

    public String getValue() { return value; }
  }
}

public final class Success extends AbstractModel {
  private ZonedDateTime enrolledAt;

  @JsonCreator
  public Success(String userId, @JsonProperty("enrolledAt") ZonedDateTime enrolledAt) {
    super(userId, Type.SUCCESS);
    this.enrolledAt = enrolledAt;
  }

  // getters
}

该应用程序基于Spring Boot，因此我正在反序列化JSON，例如：

public final class Cancel extends AbstractModel {
  private ZonedDateTime cancelledAt;

  private String reason;

  @JsonCreator
  public Cancel(String userId, @JsonProperty("cancelledAt") ZonedDateTime cancelledAt,
      @JsonProperty("reason") String reason) {
    super(userId, Type.CANCEL);
    this.cancelledAt = cancelledAt;
    this.reason = reason;
  }

  // getters
}

...但是最终由于我要在此处发布此消息，所以Jackson到目前为止都不喜欢任何一个。我已经尝试过类似@Component public final class NotificationMapper { private ObjectMapper mapper; public NotificationMapper(final ObjectMapper mapper) { this.mapper = mapper; } public Optional<Notification<? extends AbstractModel>> deserializeFrom(final String thiz) { try { return Optional.of(mapper.readValue(thiz, new NotificationTypeReference())); } catch (final Exception e) { /* log errors here */ } return Optional.empty(); } private static final class NotificationTypeReference extends TypeReference<Notification<? extends AbstractModel>> { } }和JsonTypeInfo这样的事情，但是我无法更改JSON输入。

有人吗？有任何线索吗？

Answer 1

我们最终在JSON中添加了另一个键/值对–确实对合同进行了一些修改以适应该“私有”键/值对。

无论如何，如果有人遇到相同的问题，这是该方法的解决方案：

...
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonSubTypes;
import com.fasterxml.jackson.annotation.JsonTypeInfo;

@JsonIgnoreProperties("_type")
@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "_type")
@JsonSubTypes({
  @JsonSubTypes.Type(value = Cancel.class, name = "_type"),
  @JsonSubTypes.Type(value = Fail.class, name = "_type"),
  @JsonSubTypes.Type(value = Success.class, name = "_type"),
})
public abstract class AbstractModel {
  private String userId;

  private Type type;

  AbstractModel() { }

  AbstractModel(final String userId, final Type type) {
    this.userId = userId;
    this.type = type;
  }

  // getters, toString, etc.

  public enum Type {
    CANCEL("event.cancelled"),
    FAIL("event.failed"),
    SUCCESS("event.success");

    private final String value;

    Type(String value) {
      this.value = value;
    }

    public String getValue() { return value; }
  }
}

无法使用杰克逊反序列化通用类层次结构

1 个答案: