在Spring Boot中无法从REST API返回错误代码和消息

Question

我是Spring Boot的新手。我已经在Spring Boot中实现了以下rest api：

 @GetMapping(value = "/output")
 public ResponseEntity<?> getListOfPOWithItem(@QueryParam("input1") String input1,
                                        @QueryParam("input2") String input2)
                                   throws  BusinessException {
 if (input1 == null) {
  throw new BusinessException("Query param input1 is null or invalid");
 }
 if (input2 == null) {
  throw new BusinessException("Query param input2 is null or invalid");
 }


 List<Output> outputList = 

   myService.getDetails(input1, input2);

   if (outputList != null) {
       return new ResponseEntity<List<Ouput>>(outputList, HttpStatus.OK);
   }
   return ResponseEntity.status(HttpStatus.NO_CONTENT).build();
 }

Myservice中的

getDetails（）定义如下：

public List<Output> getDetails(String input1, String input2)
      throws BusinessException {
String path = new StringBuilder().append(getBaseUrl()).append("/input1/")
        .append(input1).append("/input2/").append(input2).toString();
try {
  ResponseEntity<List<Output>> responseEntityList = restTemplate.exchange(path,
          HttpMethod.GET, null, new ParameterizedTypeReference<List<Output>>() {});
  List<Output> outputList = responseEntity.getBody();

  if (responseEntityList.isEmpty()) {
    throw new EntityNotFoundException("Input not found",
        ExternalServicesErrorCode.NO_DATA_FOUND);
  }
  return outputList;

} catch (HttpStatusCodeException e) {
  int statusCode = e.getStatusCode().value();

  if (statusCode == Status.NOT_FOUND.getStatusCode()) {
    throw new EntityNotFoundException("Data not found",
        ExternalServicesErrorCode.NO_DATA_FOUND);

  } else {
    throw new BusinessException("Error in getting data", ExternalServicesErrorCode.SERVICE_ERROR);
  }
}

}

问题是：调用此API进行无效输入时，我得到500，而不是404和错误消息“找不到数据”。谁能建议我在上面的代码中进行哪些更改？

编辑：根据建议，我添加了以下课程：

@RestControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {

 @ExceptionHandler(Exception.class)
 public final ResponseEntity<ExceptionResponse> 
  handleAllExceptions(Exception ex,
  WebRequest request) {

 ExceptionResponse exceptionResponse = new ExceptionResponse(Instant.now().toEpochMilli(),
    ex.getMessage(), request.getDescription(true));
  return new ResponseEntity<>(exceptionResponse, HttpStatus.INTERNAL_SERVER_ERROR);
 }

@ExceptionHandler(EntityNotFoundException.class)
 public final ResponseEntity<ExceptionResponse> handleEntityNotFoundException(
  EntityNotFoundException ex, WebRequest request) {

   ExceptionResponse exceptionResponse = new ExceptionResponse(Instant.now().toEpochMilli(),
    ex.getMessage(), request.getDescription(true));
   return new ResponseEntity<>(exceptionResponse, HttpStatus.NO_CONTENT);
}

即使在那之后，我也无法按预期获得错误代码和错误消息。

Answer 1

根据您的控制器，它用来引发“ BusinessException”异常。但是您尚未实现在Controller Advisor中捕获该异常的方法“ GlobalExceptionHandler”。测试成功后，请在您的控制器顾问中包括以下方法。

    @ExceptionHandler(BusinessException.class)
    public ResponseEntity<String> handleBusinessException(BusinessException businessException ) {

        return new ResponseEntity<>("Your specific error", HttpStatus.NOT_FOUND);
    }

下面是测试结果

Answer 2

您遇到的异常处理代码丢失，请参考https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/servlet/mvc/method/annotation/ResponseEntityExceptionHandler.html和https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/bind/annotation/ExceptionHandler.html

Answer 3

如果两个输入都是无效的错误消息，则应该创建组合消息，而不是引发业务异常，然后您可以返回responseEntity作为快速解决方案：
返回新的ResponseEntity <>（“无效输入”，HttpStatus.NOT_FOUND）；

Answer 4

要通过@RestControllerAdvice处理此修复程序，应创建一个自定义异常，其中包含httpStatus代码和要返回的消息

public class CustomBusinessException extends Exception{

/**
 * 
 */
private static final long serialVersionUID = 1L;

private final String status;
private final String requestMessage;
private final String description;


    public CustomBusinessException (Throwable ex,String status, String requestMessage, String description) {
    super(ex);
    this.status = status;
    this.requestMessage = requestMessage;
    this.description = description;
}
//create getter and setter

}

通过您的自定义异常处理程序（@RestCOntrollerAdvice）处理此异常，并准备要发送的自定义响应

@ExceptionHandler({ CustomBusinessException .class })
public ResponseEntity<CustomBusinessResponse> handleAll(CustomBusinessException customBusinessException , WebRequest request) {

    logger.error("Exception occured in NRACustomExceptionHandler :"+ExceptionUtils.getStackTrace(nraGatewayException));
    CustomBusinessResponse response = new CustomBusinessResponse();
    response.setMessage(customBusinessException.getRequestMessage());
    response.setDescription(customBusinessException.getDescription());

    return new ResponseEntity<>(response, new HttpHeaders(), HttpStatus.valueOf(Integer.parseInt(customBusinessException.getStatus())));
}

创建自定义响应类

public class NRAExceptionResponse {

private String message;

private String description;


//create getter and setter
}

抛出自定义异常，其状态将以这种方式发送

  throw new NRAGatewayException(e, "404","Invalid Input", "Invalid input 1 and input 2");