五、JSR303后端校验及自定义注解

@Null @NotNull
可以在注解的括号中定义自己的message提示

@Data
@TableName("pms_brand")
public class BrandEntity implements Serializable {
	private static final long serialVersionUID = 1L;

	
	@Null(message = "新增不能指定ID",groups = {AddGroup.class})
	@NotNull(message = "修改必须指定id",groups = {UpdateGroup.class})
	@TableId
	private Long brandId;
	
	@NotBlank(message = "品牌名不能为空",groups = {AddGroup.class,UpdateGroup.class})
	private String name;
	
	@NotEmpty(message = "logo不能为空",groups = {AddGroup.class})
	@URL(message = "logo必须是一个合法的url",groups = {AddGroup.class,UpdateGroup.class})
	private String logo;
	
	private String descript;
	
	@NotNull(groups = {AddGroup.class, UpdateStatusGroup.class})
	@ListValue(vals={0,1},groups = {AddGroup.class, UpdateStatusGroup.class})
	private Integer showStatus;
	
	@NotEmpty(groups = {AddGroup.class})
	@Pattern(regexp = "^[a-zA-Z]$",message = "检索首字母必须是一个字母",groups = {AddGroup.class,UpdateGroup.class})
	private String firstLetter;
	
	@NotNull(groups = {AddGroup.class})
	@Min(value = 0,message = "排序必须大于等于0",groups = {AddGroup.class,UpdateGroup.class})
	private Integer sort;

}

（1）controller接口

 public R save(@Validated({AddGroup.class}) @RequestBody BrandEntity brand){

（2）实体类

@NotBlank(message = "品牌名不能为空",groups = {AddGroup.class,UpdateGroup.class})

（3）默认没有指定分组的校验注解@NotBlank，在分组校验情况下不生效，只会在@Validated生效

@Validated({AddGroup.class}) 可以指定校验的组
@Valid

@RequestMapping("/save")
    public R save(@Validated({AddGroup.class}) @RequestBody BrandEntity brand){
        brandService.save(brand);

        return R.ok();
    }

就可以获取到校验的结果

public R save(@Valid @RequestBody BrandEntity brand, BindingResult result){

@RestControllerAdvice 此注解是统一处理异常的注解
是由ResponseBody ControllerAdvice组合而成的

接下来对异常的信息进行整理组合成返回值

@Slf4j
@RestControllerAdvice(basePackages = "com.atguigu.gulimall.product.controller")
public class GulimallExceptionControllerAdvice {
    @ExceptionHandler(value = MethodArgumentNotValidException.class)
    public R handleValidException(MethodArgumentNotValidException e){
        log.error("数据校验出现问题{}，异常类型：{}",e.getMessage(),e.getClass());
        BindingResult bindingResult = e.getBindingResult();
        HashMap errorMap = new HashMap<>();
        bindingResult.getFieldErrors().forEach((fieldError) -> {
            errorMap.put(fieldError.getField(),fieldError.getDefaultMessage());
        });
        return R.error(BizCodeEnum.VALID_EXCEPTION.getCode(),BizCodeEnum.VALID_EXCEPTION.getMsg()).put("data",errorMap);
    }

    @ExceptionHandler(value = Throwable.class)
    public R handleException(Throwable throwable){
        log.error("错误：",throwable);
        return R.error(BizCodeEnum.UNKNOWN_EXCEPTION.getCode(),BizCodeEnum.UNKNOWN_EXCEPTION.getMsg());
    }
}

@Documented
@Constraint(validatedBy = { ListValueContraintValidator.class }) //指定一下使用哪个校验器
@Target({ METHOD, FIELD, ANNOTATION_TYPE, CONSTRUCTOR, PARAMETER, TYPE_USE })
@Retention(RUNTIME)
public @interface ListValue {
    String message() default "{com.atguigu.valid.ListValue.message}";

    Class[] groups() default { };

    Class[] payload() default { };

    int[] vals() default {
    };
}

//校验器
public class ListValueContraintValidator implements ConstraintValidator {
    private Set set = new HashSet<>();
    //初始化方法
    @Override
    public void initialize(ListValue constraintAnnotation) {
        int[] vals = constraintAnnotation.vals();
        for (int val : vals) {
            set.add(val);
        }
    }


    //判断是否校验成功

    
    @Override
    public boolean isValid(Integer value, ConstraintValidatorContext context) {
        return set.contains(value);
    }
}