java后端优雅进行参数校验

╰半橙微兮° 2023-06-30 09:12 54阅读 0赞

# java后端优雅进行参数校验 #

利用注解的方式进行验证前端传入参数：

public class UavAddDto { 
    
        // import javax.validation.constraints.*;
        
        @NotNull(message = "姓名不允许为null")
        @NotEmpty(message = "姓名不允许为空,请检查后重新重新传入值")
        public String name;
        
        @NotNull(message = "传入数据不允许为空")
        @Min(value = 0, message = "传入数据有误，数据必须在 0~100之内")
        @Max(value = 100, message = "传入数据有误，数据必须在 0~100之内")
        public Integer count;
        
        @Email(message = "传入邮件格式有误，请检查")
        public String email;
        
        @Length(min = 11, max = 11, message = "传入的电话号码长度有误，必须为11位")
        public String mobile;
        
    }

加上 **@Valid** 注解，开启对传入对象的验证

@RestController
    public class UavController { 
    
        @Autowired
        private UavService uavService;
    
        @PostMapping("/add")
        public String add(@RequestBody @Valid UavAddDto uavAddDto) { 
            uavService.saveOne(uav);
            return "Success";
        }

验证对传入参数的检查结果：

![format_png][]**结果返回的结果太长，不符合我们传递给前端的结果。**

这里我们做**全局的异常拦截**，只将错误的信息返回给前端。

@ControllerAdvice
    @ResponseBody
    public class GlobalExceptionInterceptor { 
    
        @ExceptionHandler(value = MethodArgumentNotValidException.class)
        public ExecutionResponse exceptionHandler(HttpServletRequest request, Exception e) { 
            ExecutionResponse executionResponse = new ExecutionResponse();
            String failMsg = null;
            if (e instanceof MethodArgumentNotValidException) { 
                // 拿到参数校验具体异常信息提示
                failMsg = ((MethodArgumentNotValidException) e).getBindingResult().getFieldError().getDefaultMessage();
                executionResponse.setFailed(failMsg);
            }
            // 将消息返回给前端
            return executionResponse;
        }
    
    }

返回体：

// 返回体 这里用了 lombok 插件
    @Getter
    @Setter
    public class ExecutionResponse { 
    
        private Integer code = ResponseCodeEnum.RESPONSE_SUCCESS.code() ;
    
        private String message = "操作成功";
    
        public void setFailed(String message){ 
            this.code = ResponseCodeEnum.RESPONSE_FAILED.code();
            this.message = message;
        }
    }

添加异常拦截器后结果为：

![format_png 1][]

这样就优雅的将错误结果返回给前端。

[format_png]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9yYXcuZ2l0aHVidXNlcmNvbnRlbnQuY29tL3NwcmluZ3piL3BpY3R1cmVXYXJlaG91c2UvbWFzdGVyLzIwMjAwMTE2MTYzNTM1LnBuZw?x-oss-process=image/format,png
[format_png 1]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9yYXcuZ2l0aHVidXNlcmNvbnRlbnQuY29tL3NwcmluZ3piL3BpY3R1cmVXYXJlaG91c2UvbWFzdGVyLzIwMjAwMTE2MTYzMjExLnBuZw?x-oss-process=image/format,png