使用RestTemplate在REST API调用中对类对象内的列表具有空响应

Question

因此，我正在使用REST客户端，该客户端使用REST API来使用Spring RestTemplate获取JSON对象。所以我得到一个HTTP 200 OK响应，但是类对象内的列表（设备）为空。但是其他领域也被获取。当我使用邮递员执行相同的请求时，效果很好。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

CloverBusinessEquipments模型类：

private List<CloverBusinessEquipment> elements;

// relevant getters and setters

CloverBusinessEquipment模型类：

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"
        }
     ]
   }
}