java - 如何在 Spring 框架前端接收验证消息？

Question

我有验证限制:

 @Size(min = 3, message = "First name '${validatedValue} must be minimum 3 characters long'")
    @Pattern(regexp = "^A(\\w)+$", message = "First name must start with capital letter")
    private String firstName;

在 Controller 中，我为请求正文参数添加了 @Valid 注释。 如果验证失败 - Spring 会解决此问题，但我没有收到消息。 为什么会发生这种情况？

我尝试添加此处理程序:

    @ExceptionHandler(ConstraintViolationException.class)
    public ResponseEntity<String> handle(ConstraintViolationException constraintViolationException) {
        Set<ConstraintViolation<?>> violations = constraintViolationException.getConstraintViolations();
        String errorMessage = "";
        if (!violations.isEmpty()) {
           ...
        } else {
            errorMessage = "ConstraintViolationException occured.";
        }

        return new ResponseEntity<>(errorMessage, HttpStatus.BAD_REQUEST);
    }

Answer 1

我想，通过获取字段错误是可能的。

希望下面的示例能够成功

@ExceptionHandler(MethodArgumentNotValidException.class)
public ResponseEntity<ResponseBuilder> handleMethodArgumentNotValidException(HttpServletRequest request,
            MethodArgumentNotValidException ex) {

    BindingResult result = ex.getBindingResult();
    List<org.springframework.validation.FieldError> fieldErrors = result.getFieldErrors();
    String errorMessage = messageSource.getMessage(ApiResponseCode.ERR_COMMON_REQ_BODY.getCode(),
                new Object[] {
                        fieldErrors.stream().map(field -> field.getDefaultMessage()).collect(Collectors.joining(",")) },
                Locale.US);
    LOGGER.error(errorMessage, ex);
    return new ResponseEntity<ResponseBuilder>(
                new ResponseBuilder.Builder(ApiResponseCode.ERR_COMMON_REQ_BODY.getCode(), errorMessage).build(),
                HttpStatus.OK);
    }