无法将JSON数据解析为POJO

我有以下结构的JSON数据。我尝试过用相同的结构和名称创建POJO。我使用了一个DTO，它包含一个列表（在下面的JSON中，DTO具有数字对象的结构）和一个字符串“Notice”。我无法获取DTO中的数据

{
    "notice": "This API is in a pre-launch state, and will go through significant changes.",
    "1": {
        "next_renewal_date": "2014-08-01",
        "next_renewal_fee": {
            "price": "800.0",
            "currency": "USD"
        },
        "next_renewal_description": "1st Annuity - Official Fee",
        "next_per_claim_fee": {
            "price": "0.0",
            "currency": "USD",
            "free_claims": 0,
            "claim_type": "claims_count"
        },
        "next_agent_fee": {
            "price": "0.0",
            "currency": "USD"
        },
        "grace_period_end_date": "2015-02-01"
    },
    "2": {
        "next_renewal_date": "2018-08-01",
        "next_renewal_fee": {
            "price": "1800.0",
            "currency": "USD"
        },
        "next_renewal_description": "2nd Annuity - Official Fee",
        "next_per_claim_fee": {
            "price": "0.0",
            "currency": "USD",
            "free_claims": 0,
            "claim_type": "claims_count"
        },
        "next_agent_fee": {
            "price": "0.0",
            "currency": "USD"
        },
        "grace_period_end_date": "2019-02-01"
    }
}

POJO：

---

json和POJO不匹配。JSON字符串中缺少属性

apiCallList

结构应如下所示：

{
    "notice": "random string",
    "apiCallList": {
        "1": {
            "next_renewal_date": "2014-08-01",
             ...
        },
        "2": {
            "next_renewal_date": "2014-08-01",
             ....
        }
    }
}

---

我找到了一条路。谢谢你的帮助。 我已使用以下方法将JSON转换为Hashmap： Map data=mapper.readValue（json，Map.class）；

---

然后迭代映射，使用对象填充POJO。

通过自定义反序列化器，您可以通过Jackson实现所需的功能，如下所示：

public class CustomDeserializer extends JsonDeserializer<RenewalAPICallListDTO> {

    private static final ObjectMapper mapper = new ObjectMapper();

    static {
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    }

    @Override
    public RenewalAPICallListDTO deserialize(JsonParser jp, DeserializationContext ctxt)
            throws IOException {


        JsonNode node = jp.getCodec().readTree(jp);

        Iterator<Entry<String, JsonNode>> nodeIterator = node.fields();

        RenewalAPICallListDTO dto = new RenewalAPICallListDTO();
        Map<Integer, JsonCallDto> map = new HashMap<>();

        while (nodeIterator.hasNext()) {
            Map.Entry<String, JsonNode> entry = nodeIterator.next();
            if (entry.getKey().equalsIgnoreCase("notice")) {
                dto.setNotice(entry.getValue().toString());
            } else {
                map.put(Integer.parseInt(entry.getKey()), mapper.readValue(entry.getValue().toString(), JsonCallDto.class));
            }
        }
        dto.setApiCallList(map);
        return dto;
    }

}

---

即使已经设置了正确的类型，最终的

dto

也将按照您的意愿正确序列化。

显示您的POJO以及您用于解析json的任何内容。Gson Gson=new Gson（）；RenewalAPICallListDTO respDto=gson.fromJson（response1.toString（），RenewalAPICallListDTO.class）；public类RenewalAPICallListDTO{private Map apiCallList；public Map getApiCallList（）{return apiCallList；}public void setApiCallList（Map apiCallList）{this.apiCallList=apiCallList；}private String notice；public String getNotice（）{return notice；}public void setNotice（String notice）{this.notice=notice；}}编辑您的答案并添加正确格式的信息。JSONCallDto在JSON数据中有编号对象的进一步结构是的，这应该解决了问题，但我不能更改JSON。

{
    "notice": "random string",
    "apiCallList": {
        "1": {
            "next_renewal_date": "2014-08-01",
             ...
        },
        "2": {
            "next_renewal_date": "2014-08-01",
             ....
        }
    }
}

public class CustomDeserializer extends JsonDeserializer<RenewalAPICallListDTO> {

    private static final ObjectMapper mapper = new ObjectMapper();

    static {
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    }

    @Override
    public RenewalAPICallListDTO deserialize(JsonParser jp, DeserializationContext ctxt)
            throws IOException {


        JsonNode node = jp.getCodec().readTree(jp);

        Iterator<Entry<String, JsonNode>> nodeIterator = node.fields();

        RenewalAPICallListDTO dto = new RenewalAPICallListDTO();
        Map<Integer, JsonCallDto> map = new HashMap<>();

        while (nodeIterator.hasNext()) {
            Map.Entry<String, JsonNode> entry = nodeIterator.next();
            if (entry.getKey().equalsIgnoreCase("notice")) {
                dto.setNotice(entry.getValue().toString());
            } else {
                map.put(Integer.parseInt(entry.getKey()), mapper.readValue(entry.getValue().toString(), JsonCallDto.class));
            }
        }
        dto.setApiCallList(map);
        return dto;
    }

}

public static void main(String[] args) throws Exception {

    ObjectMapper mapper = new ObjectMapper();
    SimpleModule module = new SimpleModule();
    module.addDeserializer(RenewalAPICallListDTO.class, new CustomDeserializer());
    mapper.registerModule(module);

    RenewalAPICallListDTO dto = mapper.readValue(JSON, RenewalAPICallListDTO.class);
}