如何使用RestTemplate交换获取数据?

Question

我目前正在发送一个GET request，它在响应中返回一个null体。

@Service
public class CarService {
private RestTemplate restTemplate;
private final String url = "url";
private final String accessToken = "x";
@Autowired
public CarService () throws URISyntaxException {
restTemplate = new RestTemplate();
}
public void fetchCars() throws URISyntaxException {
HttpHeaders headers = new HttpHeaders();
headers.setBearerAuth(accessToken);
headers.setAccept(List.of(MediaType.APPLICATION_JSON));
ResponseEntity<CarList> carList = restTemplate.exchange
(RequestEntity.get(new URI(url)).headers(headers).build(), CarList.class);
}
}

CarList.class是这样的:

@JsonIgnoreProperties(ignoreUnknown = true)
public class CarList{
private List<Car> carList;
public CarList(List<Car> carList) {
this.carList= carList;
}
public CarList() {
}
public List<Car> getCarList() {
return carList;
}
@Override
public String toString() {
return "CarList{" +
"carList=" + carList +
'}';
}
}

邮差的响应是这样的:

{
"cars": [
{
"carUid": "aaaa-ccc-dd-cc-ee",
"model": "hyundai",
"price": 20000,
"soldAt": "2021-09-24T22:10:15.307Z"
}
]
}

我错过了什么吗?这是我第一次尝试从客户端消费，所以考虑一下我可能遗漏的最基本的东西。

我已经用给定的accessToken测试了Postman中的GET请求，它工作得很好。

Answer 1

你的carList对象是私有的，试着为这个对象提供一个setter方法，如果契约是好的，反序列化将工作得很好。

@JsonIgnoreProperties(ignoreUnknown = true)
public class CarList{
private List<Car> carList;
public CarList(List<Car> carList) {
this.carList= carList;
}
public CarList() {
}
public List<Car> getCarList() {
return carList;
}
public setCarList(List<Car> carList) {
this.carList= carList;
}
@Override
public String toString() {
return "CarList{" +
"carList=" + carList +
'}';
}
}