@Valid 和 @Validated

1. @Valid 和 @Validated 注解都用于字段校验
2. @Valid 所属包为：javax.validation.Valid ; @Validated 所属包为 org.springframework.validation.annotation.Validated
3. @Validated 是 @Valid 的一次封装，是Spring提供的校验机制使用。@Valid 不提供分组功能

@Validated的特殊用法

当一个实体类需要多种验证方式时，例：对于一个实体类的id来说，新增的时候是不需要的，对于更新时是必须的

    public class Attachment {
        @Id
        @NotBlank(message = "id can not be blank!", groups = {All.class, Update.class})
        private String id;

        @NotBlank(message = "fileName can not be blank!", groups = {All.class})
        private String fileName;

        @NotBlank(message = "filePath can not be blank!", groups = {All.class})
        private String filePath;

        @Field
        private byte[] data;

        @NotBlank(message = "metaData can not be empty!", groups = {All.class})
        private String metaData;

        @NotBlank(message = "uploadTime can not be blank!", groups = {All.class})
        private String uploadTime;

        public Attachment(@NotBlank(message = "id can not be blank!", groups = {All.class, Update.class}) String id) {
            this.id = id;
        }

        public interface All {
        }

        public interface Update {
        }
    }

单独对 groups 进行校验

    /**
     * 添加附件
     */
    @PostMapping("addAttachment")
    public MessageBody addAttachment(@RequestParam("file") final MultipartFile multipartFile,
                                     @Validated(Attachment.All.class) Attachment attachment,
                                     BindingResult results){
        return attachmentApiService.addAttachment(multipartFile,attachment,results);
    }

    /**
     * 更新单个附件
     */
    @PostMapping("updateAttachment")
    public MessageBody updateAttachment(@RequestParam(value = "file",required = false) final MultipartFile multipartFile,
                                        @Validated(Attachment.Update.class) Attachment attachment){
        return attachmentApiService.updateAttachment(multipartFile,attachment);
    }

使用注意

1. 校验的注解中不分配 groups，默认每次都要进行验证
2. @Validated 没有添加 groups 属性时，默认验证没有分组的验证属性
3. @Validated 添加特定 groups 属性时,只校验该注解中分配了该 groups 的属性
4. 一个功能方法上处理多个模型对象时，需添加多个验证结果对象,如下所示

    @RequestMapping("/addPeople")  
    public @ResponseBody String addPeople(@Validated People p,BindingResult result,@Validated Person p2,BindingResult result2)  {
    }