秒杀场景_解决秒杀超卖问题_04

雨点打透心脏的1/2处 2022-09-07 04:58 162阅读 0赞

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### 文章目录 ###

*   *   *   *   *  一、商品微服务改造
                 *  二、秒杀微服务改造
                 *   *  2.1. SkillGoodService 改造
                     *  2.2. MutilThreadOrder 改造

##### 一、商品微服务改造 #####

SkillGoodService改造

package com.gblfy.service;
    
    import com.gblfy.dao.SkillGoodRepository;
    import com.gblfy.entity.SkillGood;
    import lombok.RequiredArgsConstructor;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.data.redis.core.RedisTemplate;
    import org.springframework.scheduling.annotation.Scheduled;
    import org.springframework.stereotype.Component;
    import org.springframework.util.CollectionUtils;
    
    import java.util.ArrayList;
    import java.util.List;
    import java.util.Set;
    
    @Component
    public class SkillGoodService { 
    
        @Autowired
        private RedisTemplate redisTemplate;
        public static final String SKILL_GOODS_PHONE = "SKILL_GOODS_PHONE";
        public static final String SKILL_GOODS_QUEUE = "SKILL_GOODS_QUEUE";
    
        @Autowired
        private SkillGoodRepository skillGoodRepository;
    
        /**
         * 每五秒执行一次 将需要参与秒杀的商品列表加载到内存
         */
        @Scheduled(cron = "0/5 * * * * ?")
        public void prepareGood() { 
            System.out.println("开始加载商品");
            //获取所有已经在内存当中的商品ID列表
            Set<Long> set = redisTemplate.boundHashOps(SKILL_GOODS_PHONE).keys();
            List<Long> ids = new ArrayList<>();
            for (Long id : set) { 
                ids.add(id);
            }
            List<SkillGood> list = null;
            //只查询出不在内存当中的商品信息，并加载到内存
            if (CollectionUtils.isEmpty(ids)) { 
                list = skillGoodRepository.findSkillAll();
            } else { 
                list = skillGoodRepository.findSkill(ids);
            }
            if (!CollectionUtils.isEmpty(list)) { 
                for (SkillGood skillGood : list) { 
                    redisTemplate.boundHashOps(SKILL_GOODS_PHONE).put(skillGood.getId(), skillGood);
                    redisTemplate.boundListOps(SKILL_GOODS_QUEUE+skillGood.getId()).leftPushAll(convertoArry(skillGood.getStockCount(),skillGood.getId()));
                }
            }
            // 查看当前缓存中所有的商品信息
            Set keys = redisTemplate.boundHashOps(SKILL_GOODS_PHONE).keys();
            for (Object s : keys) { 
                SkillGood skillGood = (SkillGood) redisTemplate.boundHashOps(SKILL_GOODS_PHONE).get(s);
                System.out.println(skillGood.getName() + " 库存剩余：" + skillGood.getStockCount());
            }
        }
    
        private Long[] convertoArry(Integer stockCount, Long id) { 
            Long[] idslong=new Long[stockCount];
            for(int i=0;i<stockCount;i++){ 
                idslong[i]=id;
            }
            return idslong;
        }
    
        // 提供查询商品信息的方法
        public SkillGood queryProduct(Long productId) { 
            return (SkillGood) redisTemplate.boundHashOps(SKILL_GOODS_PHONE).get(productId);
        }
        // 更新商品信息
        public void update(SkillGood skillGood) { 
            skillGoodRepository.save(skillGood);
        }
    }

##### 二、秒杀微服务改造 #####

###### 2.1. SkillGoodService 改造 ######

package com.gblfy.service;
    
    import com.gblfy.dao.SkillOrderRepository;
    import com.gblfy.entity.SkillEntity;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.data.redis.core.RedisTemplate;
    import org.springframework.stereotype.Service;
    
    import javax.transaction.Transactional;
    import java.util.UUID;
    
    @Service
    public class SkillGoodService { 
    
        public static final String SKILL_GOODS_PHONE = "SKILL_GOODS_PHONE";
        public static final String SKILL_GOODS_LIST = "SKILL_GOODS_LIST";
        public static final String SKILL_GOODS_ONLY = "SKILL_GOODS_ONLY";
        public static final String SKILL_GOODS_QUEUE = "SKILL_GOODS_QUEUE";
    
        @Autowired
        private RedisTemplate redisTemplate;
        @Autowired
        private SkillOrderRepository skillOrderRepository;
        @Autowired
        private ProductService productService;
        @Autowired
        private MutilThreadOrder mutilThreadOrder;
    
        @Transactional
        public void add(Long productId, String userId) throws Exception { 
            //判断这个用户是否参加过抢单
            userId = UUID.randomUUID().toString();
            Long time = redisTemplate.boundHashOps(SKILL_GOODS_ONLY).increment(userId, 1L);
            if (time > 1) { 
                throw new Exception("重复抢单，不要太贪心");
            }
            // 先封装对象 并且放入redis 队列
            SkillEntity skillEntity = new SkillEntity();
            skillEntity.setProductId(productId);
            skillEntity.setUserId(userId);
            redisTemplate.boundListOps(SKILL_GOODS_LIST).leftPush(skillEntity);
            mutilThreadOrder.createOrder();
    
        }
    }

###### 2.2. MutilThreadOrder 改造 ######

package com.gblfy.service;
    
    import com.gblfy.dao.SkillOrderRepository;
    import com.gblfy.entity.SkillEntity;
    import com.gblfy.entity.SkillGood;
    import com.gblfy.entity.SkillOrder;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.data.redis.core.RedisTemplate;
    import org.springframework.scheduling.annotation.Async;
    import org.springframework.stereotype.Component;
    
    import java.util.Date;
    
    @Component
    public class MutilThreadOrder { 
        @Autowired
        private ProductService productService;
        @Autowired
        private SkillOrderRepository skillOrderRepository;
        @Autowired
        private RedisTemplate redisTemplate;
    
    
        @Async
        public void createOrder() throws Exception { 
            System.out.println("开始异步抢单");
            SkillEntity skillEntity = (SkillEntity) redisTemplate.boundListOps(SkillGoodService.SKILL_GOODS_LIST).rightPop();
            if (skillEntity == null) { 
                return;
            }
            Long productId = skillEntity.getProductId();
            String userId = skillEntity.getUserId();
            SkillGood skillGood = productService.getGoodById(productId);
            if (skillGood == null) { 
                throw new Exception("商品已经被抢光拉");
            }
            Long stockId = (Long) redisTemplate.boundListOps(SkillGoodService.SKILL_GOODS_QUEUE + productId).rightPop();
            if (stockId == null) { 
                System.out.println("该商品已被秒杀完毕");
                redisTemplate.boundHashOps(SkillGoodService.SKILL_GOODS_ONLY).delete(userId);
                redisTemplate.boundHashOps(SkillGoodService.SKILL_GOODS_PHONE).delete(skillGood.getId());
                skillGood.setStockCount(0);
                productService.update(skillGood);
                return;
            }
            SkillOrder skillOrder = new SkillOrder();
            skillOrder.setMoney(skillGood.getCostPrice());
            skillOrder.setPayTime(new Date());
            skillOrder.setStatus("0");
            skillOrder.setUserId(userId);
            skillOrder.setCreateTime(new Date());
            skillOrder.setSkillId(productId);
            skillOrderRepository.save(skillOrder);
            System.out.println("结束异步抢单");
        }
    }

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