发行Json与Jackson的映射问题

Question

I'm having some issues mapping the next json in java:

{
  "aggregations": {
    "asMap": {
      "detail": {
        "name": "detail",
        "value": 35100
      },
      "listed": {
        "name": "listed",
        "value": 618
      }
    }
  },
  "docCount": 9,
  "key": "789028",
  "keyAsNumber": 789028,
  "keyAsText": {}
}

to the next java bean:

public class RankingValue  {
    private Integer adId;
    private Integer listed;
    private Integer detail;
    ...
    ...
}

is it posible to map using jackson? What i would like is to get value inside detail to detail on bean and value inside listed to listed on bean, and finally the key value to adId. is there other alternative to map this? Best way?

Thanks in advance.

Answer 1

I guess that you have to use a custom Deserializer. This seems to work:

public class RankingValueDeserializer extends JsonDeserializer<RankingValue> {

    @Override
    public RankingValue deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
        JsonNode node = jp.getCodec().readTree(jp);
        Integer key = node.get("key").asInt();
        Integer detail = node.get("aggregations").get("asMap").get("detail").get("value").asInt();
        Integer listed = node.get("aggregations").get("asMap").get("listed").get("value").asInt();
        return new RankingValue(key, detail, listed);
    }
}

and your object will be something like

@JsonDeserialize(using = RankingValueDeserializer.class)
public class RankingValue  {

    private Integer adId;
    private Integer listed;
    private Integer detail;

    public RankingValue(Integer key, Integer listed, Integer detail) {
        this.adId = key;
        this.listed = listed;
        this.detail = detail;
    }

    @Override
    public String toString() {
        return "RankingValue [adId=" + adId + ", listed=" + listed
                + ", detail=" + detail + "]";
    }

}