自定义注解实现验证信息的功能

• 导包

        
        
            org.springframework.boot
            spring-boot-starter-validation
        

• 定义BO对象，前端传来的业务对象，对象中的属性需要校验

package com.imooc.boapi;

//import com.imooc.annotationcustom.VlogId;
import com.imooc.annotationcustom.VlogId;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
public class VlogBOApi {
    private String id;
   @VlogId(message = "用户不存在，禁止插入视频")
    private String vlogerId;
    private String url;
    private String cover;
    private String title;
    private Integer width;
    private Integer height;
    private Integer likeCounts;
    private Integer commentsCounts;
}

• 定义一个校验注解

package com.imooc.annotationcustom;




import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target({ ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = VlogIdValidator.class) //校验的逻辑处理类
public @interface VlogId {
    String message();

    
    Class[] groups() default {};

    
    Class[] payload() default {};
}

• 同时需要一个校验类，实现一个注解检验的逻辑

package com.imooc.annotationcustom;

import com.imooc.mapper.UsersMapper;
import com.imooc.pojo.Users;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

@Slf4j
@Component
public class VlogIdValidator implements ConstraintValidator {


    @Autowired
    UsersMapper usersMapper;

    @Override
    public void initialize(VlogId constraintAnnotation) {
        log.info("注解逻辑初始化");
    }

    @Override
    public boolean isValid(String s, ConstraintValidatorContext constraintValidatorContext) {
        Users user = new Users();
        user.setId(s);
        Users reslut = usersMapper.selectByPrimaryKey(user);
        System.out.println("注解拦截生效+package com.imooc.annotationcustom;");
        if (reslut == null) {
            return false;
        } else {
            return true;
        }
    }

}

• 业务代码

    @PostMapping("publish")
    public GraceJSONResult publish(@Valid @RequestBody VlogBOApi vlogBO) {

//        vlogService.createVlog(vlogBO);
        return GraceJSONResult.ok();
    }

• 校验失败异常，定义一个全局异常捕获，将这个错误返回给前端

    @ExceptionHandler(MethodArgumentNotValidException.class)
    @ResponseBody
    public GraceJSONResult returnMethodArgumentNotValid(MethodArgumentNotValidException e) {
        BindingResult result = e.getBindingResult();
        Map map = getErrors(result);
        return GraceJSONResult.errorMap(map);
    }

目的：做一个点赞次数拦截的功能。过程：需要拦截以后自行确定多少时间内的点赞次数

• 定义注解：

package com.imooc.annotationcustom;


import java.lang.annotation.*;


@Inherited
@Documented
@Target({ElementType.FIELD, ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface RequestLimit {
    
    int second() default 10;

    

    int maxCount() default 5;
}

• 拦截器代码，这里需要获取接口上的自定义注解handlerMethod.getMethodAnnotation

        if (handler instanceof HandlerMethod) {
            HandlerMethod handlerMethod =  (HandlerMethod) handler;
            //获取RequestLimit注解
            RequestLimit requestLimit = handlerMethod.getMethodAnnotation(RequestLimit.class);
            if (null == requestLimit) {
                System.out.println("没有获取到注解");
                return true; //每加注解说明没有限制，多少次都ok
            }
            //限制的时间范围
            int seconds = requestLimit.second();
            //限制时间内的最大次数
            int maxCount = requestLimit.maxCount();
            //获取用户ip
            String userIp = IPUtil.getRequestIp(request);
            //判断redis中是否有ip
            boolean keyIsExist = redis.keyIsExist(LIKE_VLOG_OPERATE_COUNT + ":" + userIp);

            //如果没有这个键，说明当前用户在20s内没有点过赞,因为这个拦截器就是拦截点赞的后端接口，所以如果没有这个键就设置一个键
            if (keyIsExist == false) {
                redis.set(LIKE_VLOG_OPERATE_COUNT + ":" + userIp, "0", seconds);
                System.out.println("ok");
                return  true;
            }
            // 返回true，就要判断这个键对应的值的个数
            String res = redis.get(LIKE_VLOG_OPERATE_COUNT + ":" + userIp);
            if (Integer.valueOf(res) >= maxCount) {
                GraceException.display(ResponseStatusEnum.LIKE_VLOG_WAIT_ERROR);
                return false;
            }
        }





        return true;
    }

• 业务代码

    @PostMapping("like")
    //TODO: 这里需要调试
    @RequestLimit(maxCount = 3, second = 60)
    public GraceJSONResult like(@RequestParam String userId,
                                @RequestParam String vlogerId,
                                @RequestParam String vlogId,
                                HttpServletRequest request) {
        vlogService.userLikeVlog(userId, vlogId);
        redis.increment(REDIS_VLOGER_BE_LIKED_COUNTS + ":" + vlogerId, 1);
        redis.increment(REDIS_VLOG_BE_LIKED_COUNTS + ":" + vlogId, 1);

        redis.set(REDIS_USER_LIKE_VLOG + ":" + userId + ":" + vlogId, "1");

        //------------------------------------------//
        //新增功能，限制点赞次数，
        String userIp = IPUtil.getRequestIp(request);
        redis.increment(LIKE_VLOG_OPERATE_COUNT + ":" + userIp,1);
        //-------------------------------------------//


        return GraceJSONResult.ok();
    }