java - 无法推断 ResponseEntity<> 的类型参数

我想实现 Spring 端点，我可以在其中返回 XML 对象 NotificationEchoResponse 和 http 状态代码。我试过这个:

@PostMapping(value = "/v1/notification", produces = "application/xml")
  public ResponseEntity<?> handleNotifications(@RequestParam MultiValueMap<String, Object> keyValuePairs) {

   if (!tnx_sirnature.equals(signature))
     {
         return new ResponseEntity<>("Please contact technical support!", HttpStatus.INTERNAL_SERVER_ERROR);
     }

    return new ResponseEntity<>(new NotificationEchoResponse(unique_id), HttpStatus.OK);
  }

但是我收到错误:Cannot infer type arguments for ResponseEntity<> 在这一行:return new ResponseEntity<>("Please contact technical support!", HttpStatus.INTERNAL_SERVER_ERROR); 你知道我如何解决这个问题吗？

最佳答案

您可以使用

    ResponseEntity<Object>

像那样

或者

您可以创建自己的自定义类，例如 ResponseData，并在该类中放置一个字段，例如 paylod

  public class ResponseData {
      private Object payload;
   }

并像那个 ResponseEntity 一样使用并设置该值。

现在你的 Controller 看起来像这样

    @PostMapping(value = "/v1/notification", produces = "application/xml")
    public ResponseEntity<ResponseData> handleNotifications(@RequestParam
    MultiValueMap<String, Object> keyValuePairs) {

   if (!tnx_sirnature.equals(signature))
   {
     return new ResponseEntity<ResponseData>(new ResponseData("Please contact to technical support"),
    HttpStatus.INTERNAL_SERVER_ERROR);
   }

   return new ResponseEntity<ResponseData>(new ResponseData(new NotificationEchoResponse(unique_id)),
   HttpStatus.OK);
   }

您也可以用 Object 替换响应数据，然后

  @PostMapping(value = "/v1/notification", produces = "application/xml")
    public ResponseEntity<Object> handleNotifications(@RequestParam
    MultiValueMap<String, Object> keyValuePairs) {

   if (!tnx_sirnature.equals(signature))
   {
     return new ResponseEntity<Object>("Please contact to technical support",
    HttpStatus.INTERNAL_SERVER_ERROR);
   }

   return new ResponseEntity<Object>(new NotificationEchoResponse(unique_id),
   HttpStatus.OK);
   }