java - 如何处理RequestMapping中的@Valid违规？

Question

我在 Java/Spring 中有以下 Rest Controller 。检查约束的有效性。然而，这些都是在到达我的“bar”方法主体之前完成的。违规案件如何处理？我可以自定义 400 响应正文吗？

@RestController
@RequestMapping("foo")
public class FooController {

    @RequestMapping(value = "bar", method = RequestMethod.POST)
    public ResponseEntity<Void> bar(@RequestBody @Valid Foo foo) {
        //body part
        return ResponseEntity.status(HttpStatus.OK).build();
    }

}

Answer 1

您应该使用controllerAdvice，这是一个示例(在kotlin中):

@ControllerAdvice
open class ExceptionAdvice {

    @ExceptionHandler(MethodArgumentNotValidException::class)
    @ResponseBody
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    open fun methodArgumentNotValidExceptionHandler(request: HttpServletRequest, e: MethodArgumentNotValidException): ErrorDto {

        val errors = HashMap<String, String>()

        for (violation in e.bindingResult.allErrors) {
            if (violation is FieldError) {
                errors.put(violation.field, violation.defaultMessage)
            }
        }

        return ErrorDto(errors)
    }

    @ExceptionHandler(BindException::class)
    @ResponseBody
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    open fun bindExceptionHandler(request: HttpServletRequest, e: BindException): ErrorDto {

        val errors = HashMap<String, String>()

        for (violation in e.bindingResult.allErrors) {
            if (violation is FieldError) {
                errors.put(violation.field, violation.defaultMessage)
            }
        }

        return ErrorDto(errors)
    }
}

它允许处理 Controller 抛出的异常，包括验证异常。