我有两个问题:

如何使用Spring RestTemplate映射JSON对象列表。 如何映射嵌套的JSON对象。

我试图消费https://bitpay.com/api/rates,从http://spring.io/guides/gs/consuming-rest/遵循教程。


当前回答

这里提到了3种检索对象列表的方法。所有这些都将完美地工作

@RequestMapping(value = "/emp2", produces = "application/json")
public List<Employee> getEmp2()
{
    HttpHeaders headers = new HttpHeaders();
    headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
    HttpEntity<String> entity = new HttpEntity<String>(headers);
    ResponseEntity<List<Employee>> response = restTemplate.exchange(
            "http://hello-server/rest/employees", HttpMethod.GET,entity, 
    new ParameterizedTypeReference<List<Employee>>() {});
    return response.getBody();
}

(或)

@RequestMapping(value = "/emp3", produces = "application/json")
public List<Employee> getEmp3()
{
    Employee[] empArray = restTemplate.getForObject("http://hello-server/rest/employees", Employee[].class);
    List<Employee> emp= Arrays.asList(empArray);
    return emp;
}

(或)

    @RequestMapping(value = "/emp4", produces = "application/json")
public Employee[] getEmp4()
{
    ResponseEntity<Employee[]> responseEntity = restTemplate.getForEntity("http://hello-server/rest/employees", Employee[].class);
    Employee[] empList = responseEntity.getBody();
    //MediaType contentType = responseEntity.getHeaders().getContentType();
    //HttpStatus statusCode = responseEntity.getStatusCode();
    return  empList;
}

Employee.class

public class Employee {

private Integer id;
private String name;
private String Designation;
private String company;

//getter setters and toString()

}

其他回答

也许这样……

ResponseEntity<Object[]> responseEntity = restTemplate.getForEntity(urlGETList, Object[].class);
Object[] objects = responseEntity.getBody();
MediaType contentType = responseEntity.getHeaders().getContentType();
HttpStatus statusCode = responseEntity.getStatusCode();

RequestMapping的控制器代码

@RequestMapping(value="/Object/getList/", method=RequestMethod.GET)
public @ResponseBody List<Object> findAllObjects() {

    List<Object> objects = new ArrayList<Object>();
    return objects;
}

ResponseEntity是HttpEntity的扩展,它添加了HttpStatus状态码。在RestTemplate和@Controller方法中使用。 在RestTemplate中,该类由getForEntity()和exchange()返回。

作为一个通用模块,Page<?>对象可以被模块反序列化,就像JodaModule, Log4jJsonModule等。参考我的回答。使用Pageable字段测试端点时出现JsonMappingException

对我来说这很有效

Object[] forNow = template.getForObject("URL", Object[].class);
    searchList= Arrays.asList(forNow);

Object是你想要的类的位置

我从这个帖子https://jira.spring.io/browse/SPR-8263找到了工作。

基于这篇文章,你可以返回一个类似这样的列表:

ResponseEntity<? extends ArrayList<User>> responseEntity = restTemplate.getForEntity(restEndPointUrl, (Class<? extends ArrayList<User>>)ArrayList.class, userId);

在我的情况下,我更喜欢提取一个字符串,然后使用JsonNode接口浏览上下文

    var response =  restTemplate.exchange("https://my-url", HttpMethod.GET, entity,  String.class);
    if (response.getStatusCode() == HttpStatus.OK) {
        var jsonString = response.getBody();
        ObjectMapper mapper = new ObjectMapper();
        JsonNode actualObj = mapper.readTree(jsonString);           
        
        System.out.println(actualObj);  
    }

或者很快

ObjectNode actualObj= restTemplate.getForObject("https://my-url", ObjectNode.class);

然后读取内部数据与路径表达式,即。

boolean b = actualObj.at("/0/states/0/no_data").asBoolean();