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java实现秒杀业务之页面级高并发优化(URL缓存和对象缓存)

程序员文章站 2022-06-20 08:36:26
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redis删除

	/**
	 * 删除
	 * */
	public boolean delete(KeyPrefix prefix, String key) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			//生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			long ret=jedis.del(realKey);
			return ret>0;
		 }finally {
			  returnToPool(jedis);
		 }
	}

对象缓存:

package com.jack.seckill.service;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.jack.seckill.dao.SeckillDao;
import com.jack.seckill.domain.SeckillUser;
import com.jack.seckill.exception.GlobalException;
import com.jack.seckill.redis.RedisService;
import com.jack.seckill.redis.SeckillUserKey;
import com.jack.seckill.result.CodeMsg;
import com.jack.seckill.util.MD5Util;
import com.jack.seckill.util.UUIDUtil;
import com.jack.seckill.vo.LoginVo;
@Service
public class SeckillUserService {
	public static final String COOKIE_NAME_TOKEN="token";
	
	@Autowired
	SeckillDao seckillDao;
	@Autowired
	RedisService redisService;
	//取数据
	public SeckillUser getById(long id) {
		//实现对象缓存
		//第一步:取缓存
		SeckillUser seckillUser=redisService.get(SeckillUserKey.getById, ""+id, SeckillUser.class);
		if(seckillUser!=null) {
			return seckillUser;
		}
		//取数据库
		seckillUser=seckillDao.getById(id);
		if(seckillUser!=null) {
			redisService.set(SeckillUserKey.getById, ""+id, seckillUser);
		}
		return seckillUser;
		//return seckillDao.getById(id);
	}
	//修改数据
	/**
	 * 注意:对象缓存如果有数据发生了更新,一定要将redis里面的缓存更新掉,否则出现数据的不一致
	 * 这也是对象缓存和页面缓存最大的区别
	 * 引用如别人的一定引用service层,而不是直接调别人的Dao,因为可能被人在service层调缓存
	 * @return
	 */
	public boolean updatePassword(String token,long id,String passwordNew) {
		//取user
		SeckillUser seckillUser=seckillDao.getById(id);
		
		if(seckillUser==null) {
			throw new GlobalException(CodeMsg.MOBILE_NOT_EXIST);
		}
		//更新数据库
		SeckillUser toBeUpdate=new SeckillUser();
		toBeUpdate.setId(id);
		toBeUpdate.setPassword(MD5Util.formPassToDBPass(passwordNew, seckillUser.getSalt()));
		seckillDao.update(toBeUpdate);
		//处理缓存
		redisService.delete(SeckillUserKey.getById,""+id);
		seckillUser.setPassword(toBeUpdate.getPassword());
		redisService.set(SeckillUserKey.token,token,seckillUser);
		return true;
	}
	
}

 

相关标签: java