validation 校验对象的属性为类

1. 问题描述：@NotNull 参数校验失效

2. 代码：

controller 接口
@PostMapping("/saveSpu")
public SHttpResponse<Boolean> saveSpu(@Valid @RequestBody ProductSaveDto productSaveDto) {
    SResponse<Boolean> re = productSpuService.saveSpu(productSaveDto);
    return SHttpResponse.transform(re);
}

对象
public class ProductSaveDto {

    @NotNull
    private ProductSpuEntity spuEntity;

    ...
}
public class ProductSpuEntity {

    @NotNull(message = "分类id不能为空")
    private Integer categoryId;
    
}

3. 解决方法：在被校验的属性类上增长注解@Vail

修改后代码
public class ProductSaveDto {

    @Valid
    @NotNull
    private ProductSpuEntity spuEntity;

    ...
}