Jackson @JsonValue 与 @JsonTypeInfo 冲突；如何让他们一起工作

Question

我正在使用Jackson 序列化POJO。这个POJO 类由一些字段和一个Map<String,Object> others 组成。我在为这个MAP 字段编写JSON 时使用Custom Serializer。我想避免得到Map field name "others"´ in my JSON. Hence, I am using the @JsonValueon theMapfield but using the@JsonValueis conflicting with@JsonTypeInfo`。我在课堂上需要这两个注释，我该如何实现？

截至目前，我得到的JSON 如下：（@JsonValue 和 @JsonTypeInfo）

[ "Customer", {
  "name" : "Rise Against",
  "google:sub" : "MyValue-1",
  "age" : "2000"
} ]

我想同时获得JSON 和@JsonValue 和@JsonTypeInfo：（如您所见others 键已提交，但其值直接添加到JSON）

{
  "isA" : "Customer",
  "name" : "Batman",
  "google:sub" : "MyValue-1",
  "age" : "2008"
}

我能够获得输出，但我需要从我的班级中删除注释：

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, visible = true, property = "isA")

但如果我删除它，我将不会在我的 JSON 中获得 isA 属性。我想知道如何使Jackson Json Serializer 与@JsonTypeInfo 和@JsonValue 一起工作。

不带@JsonTypeInfo但带@JsonValue的输出：

{
  "name" : "Rise Against",
  "google:sub" : "MyValue-1",
  "age" : "2000"
}

输出不带@JsonValue，但带@JsonTypeInfo

{
  "isA" : "Customer",
  "name" : "",
  "age" : "",
  "others" : {
    "name" : "Rise Against",
    "google:sub" : "MyValue-1",
    "age" : "2000"
  }
}

以下是我的Customer类Pojo：

@XmlRootElement(name = "Customer")
@XmlType(name = "Customer", propOrder = {"name", "age", "others"})
@XmlAccessorType(XmlAccessType.FIELD)
@NoArgsConstructor
@Getter
@Setter
@JsonInclude(JsonInclude.Include.NON_NULL)
@AllArgsConstructor
@JsonIgnoreType
@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = As.PROPERTY, visible = true, property = "isA")
public class Customer {

  @XmlElement(name = "name", required = true)
  private String name;

  @XmlElement(name = "age", required = true)
  private String age;

  @JsonSerialize(using = CustomExtensionsSerializer.class)
  @XmlJavaTypeAdapter(TestAdapter.class)
  @XmlPath(".")
  @JsonValue
  private Map<String, Object> others = new HashMap<>();

  @JsonAnySetter
  public void setOthers(String key, Object value) {
    others.put(key, value);
  }

  public Map<String, Object> getOthers() {
    return others;
  }
}

以下是我的`自定义序列化程序：

public class CustomExtensionsSerializer extends JsonSerializer<Map<String, Object>> {

  private static final ObjectMapper mapper = new ObjectMapper();

  @Override
  public void serialize(Map<String, Object> value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
    gen.writeStartObject();
    recusiveSerializer(value, gen, serializers);
    gen.writeEndObject();
  }

  public void recusiveSerializer(Map<String, Object> value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
    for (Map.Entry<String, Object> extension : value.entrySet()) {
      if (extension.getValue() instanceof Map) {
        //If instance is MAP then call the recursive method
        recusiveSerializer((Map) extension.getValue(), gen, serializers);
      } else if (extension.getValue() instanceof String) {
        //If instance is String directly add it to the JSON
        gen.writeStringField(extension.getKey(), (String) extension.getValue());
      } else if (extension.getValue() instanceof ArrayList) {
        //If instance if ArrayList then loop over it and add it to the JSON after calling recursive method
        gen.writeFieldName(extension.getKey());
        gen.writeStartObject();
        for (Object dupItems : (ArrayList<String>) extension.getValue()) {
          if (dupItems instanceof Map) {
            recusiveSerializer((Map) dupItems, gen, serializers);
          } else {
            gen.writeStringField(extension.getKey(), (String) extension.getValue());
          }
        }
        gen.writeEndObject();
      }
    }
  }
}

Answer 1

尝试将@JsonTypeInfo.include 设置为JsonTypeInfo.As.EXISTING_PROPERTY

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, visible = true, property = "isA")