它是这样完成的，用controlleradvice声明globalexceptionhandler

@ControllerAdvice
public class GlobalExceptionHandler {

@ExceptionHandler(KeyNotFoundException.class)
    public ResponseEntity<ExceptionResponse> keyNotFound(KeyNotFoundException ex) {
        ExceptionResponse response = new ExceptionResponse();
        response.setStatusCode(HttpStatus.BAD_REQUEST.toString().substring(0,3));
        response.setError(HttpStatus.BAD_REQUEST.getReasonPhrase());
        response.setMessage(ex.getMessage());
        response.setTimestamp(LocalDateTime.now());
        return new ResponseEntity<ExceptionResponse>(response, HttpStatus.BAD_REQUEST);
    }
}

keynotfoundexception异常

public class KeyNotFoundException extends RuntimeException {

    private static final long serialVersionUID = 1L;

    public KeyNotFoundException(String message) {
        super(message);
    }

}

异常响应

public class ExceptionResponse {

    private String error;
    private String message;
    private String statusCode;
    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd-MM-yyyy hh:mm:ss")
    private LocalDateTime timestamp;

// getters and setters

在api代码catch块中，您发现请求中缺少参数或键

throw new  KeyNotFoundException ("Key not found in the request..."+ex.getMessage());