使用 JSON 和 Spring RestTemplate 反序列化数字字段

Question

我正在使用 Spring 和 Resttemplate 调用 WS，并尝试将 JSON 响应解析为自定义对象。

WS调用sn-p：

RestTemplate restTemplate = new RestTemplate();

String wsURL = "https://www.dummyws.com";
String accessToken = "dummyAccessToken"

HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
headers.add("Authorization", "Bearer " + accessToken);
headers.add("Accept", "*/*");

MultiValueMap<String, String> map= new LinkedMultiValueMap<String, String>();                       
HttpEntity<MultiValueMap<String, String>> wsRequest = new HttpEntity<MultiValueMap<String, String>>(map, headers);

ResponseEntity<GetPassengersData> wsResponse = restTemplate.exchange(wsURL, HttpMethod.GET, wsRequest, GetPassengersData.class);
GetPassengersData getPassengerData = wsResponse.getBody();

WS 响应 sn-p：

{
"data" : [{
        "start" : "2018-01-01 00:00:00",
        "finish" : "2018-01-01 23:59:59",
        "total" : 1076
    }
]

}

自定义对象定义：

@JsonIgnoreProperties(ignoreUnknown = true)
public static class GetPassengersData implements Serializable
{
    private static final long serialVersionUID = 1L;

    public GetPassengersData() 
    {   
    }       

    private List<GetPassengersDataItem> data;
    public List<GetPassengersDataItem> getData() {
        return data;
    }
    public void setData(List<GetPassengersDataItem> data) {
        this.data = data;
    }
}

@JsonIgnoreProperties(ignoreUnknown = true) 
public static class GetPassengersDataItem implements Serializable
{
    private static final long serialVersionUID = 1L;

    public GetPassengersDataItem() 
    {   
    }       

    private String start;
    private String finish;
    private double total;

    public String getStart() {
        return start;
    }
    public void setStart(String start) {
        this.start = start;
    }
    public String getFinish() {
        return finish;
    }
    public void setFinish(String finish) {
        this.finish = finish;
    }
    public double getTotal() {
        return total;
    }
    public void setTotal(double total) {
        this.total = total;
    }
}

restTemplate.exchange 中出现以下异常：

org.springframework.http.converter.HttpMessageNotReadableException: Could not read JSON: Can not deserialize instance of double out of START_OBJECT token
at [Source: sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@552b744a; line: 5, column: 44] (through reference chain: *.GetPassengersData["data"]->*.GetPassengersDataItem["total"]); nested exception is org.codehaus.jackson.map.JsonMappingException: Can not deserialize instance of double out of START_OBJECT token

仅解析字符串字段效果很好。我错过了什么？我需要做什么来解析数字字段？我试过 int、long、double、BigDecimal，得到同样的异常错误。

提前致谢。

Answer 1

我不确定，但请尝试不带“数据”节点的 WS 响应

{ 
  [{
    "start" : "2018-01-01 00:00:00",
    "finish" : "2018-01-01 23:59:59",
    "total" : 1076
  }]
}

或者尝试映射到具有List<GetPassengersData> data属性的对象