java后端进行参数校验

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，不加该注解是无效的

`@RestController
public class UavController {

@Autowired
private UavService uavService;

@PostMapping("/add")
public String add(@RequestBody @Valid UavAddDto uavAddDto) {
    uavService.saveOne(uav);
    return "Success";
}

`

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
@Date
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;
}

}
`