在使用RestTemplate调用的REST API中对对象列表具有null响应

Question

因此，我正在研究一个REST客户机，它使用REST API来使用Spring RestTemplate获得一个JSON对象。因此，我得到一个HTTP200OK响应，但类对象内部的列表（设备）为空。但会提取其他字段。当我用邮递员做同样的请求时，它工作得很好。这可能是什么原因？

RestTemplate代码段：

 RestTemplate restTemplate = new RestTemplate();
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.add("Content-Type", "application/json");
requestHeaders.add("Authorization", "Bearer " + apiToken);
HttpEntity entity = new HttpEntity(requestHeaders);
ResponseEntity<CloverMerchant> response = restTemplate.exchange(getMerchantDetailsUrl, HttpMethod.GET, entity, CloverMerchant.class);
return response.getBody();

CloverMerchant模型类：

private String id;
private String name;
private String website;
private boolean isBillable;
private CloverBusinessEquipments equipment;

// other relevant getters and setters

private List<CloverBusinessEquipment> elements;

    public CloverBusinessEquipments() {
}

@JsonGetter("elements")
public List<CloverBusinessEquipment> getElements() {
    return elements;
}

private String merchantId;
private String serialNumber;
private String equipmentCode;
private String equipmentCodeDesc;
private String provisionedDeviceType;
private boolean boarded;
private boolean provisioned;

// relevant getters and setters

REST API的预期响应JSON：

{
  "id": "5ZTFCGXQKVZNA",
  "name": "xxxx",
  "website": "https://xxxx.io",
  "isBillable": false,
  "equipment": {
  "elements": [
    {
        "merchantId": "5ZTFCGXQKVZNA",
        "boarded": false,
        "provisioned": true,
        "serialNumber": "C030UQ71040182",
        "equipmentCode": "105J",
        "equipmentCodeDesc": "Clover Mini",
        "provisionedDeviceType": "MAPLECUTTER"
    },
    {
        "merchantId": "5ZTFCGXQKVZNA",
        "boarded": false,
        "provisioned": true,
        "serialNumber": "C050UQ75150054",
        "equipmentCode": "1297",
        "equipmentCodeDesc": "Clover Station 2018",
        "provisionedDeviceType": "GOLDENOAK"
       }
    ]
  }
}

Answer 1

您的模型不代表JSON响应。您试图在JSON的根级别找到具有“elements”键的JSONObject，但实际上它位于“equipment”键之后的第二个级别。

变量-Private CloverBusinessEquipments Equipments；应表示以下内容：

"equipment": {
    "elements": [
        {
            "merchantId": "5ZTFCGXQKVZNA",
            "boarded": false,
            "provisioned": true,
            "serialNumber": "C030UQ71040182",
            "equipmentCode": "105J",
            "equipmentCodeDesc": "Clover Mini",
            "provisionedDeviceType": "MAPLECUTTER"
        },
        {
            "merchantId": "5ZTFCGXQKVZNA",
            "boarded": false,
            "provisioned": true,
            "serialNumber": "C050UQ75150054",
            "equipmentCode": "1297",
            "equipmentCodeDesc": "Clover Station 2018",
            "provisionedDeviceType": "GOLDENOAK"
        }
    ]
}

但是您已经为POJO建模，它认为equipments变量如下所示：

"elements": 
        {
            "merchantId": "5ZTFCGXQKVZNA",
            "boarded": false,
            "provisioned": true,
            "serialNumber": "C030UQ71040182",
            "equipmentCode": "105J",
            "equipmentCodeDesc": "Clover Mini",
            "provisionedDeviceType": "MAPLECUTTER"
        }