添加redis解决暴露秒杀地址时的高并发

Author: codingXiaxw

src/main/java/cn/codingxiaxw/dao/cache/RedisDao.java

@@ -1,7 +1,71 @@
 package cn.codingxiaxw.dao.cache;
 
+import cn.codingxiaxw.entity.Seckill;
+import com.dyuproject.protostuff.LinkedBuffer;
+import com.dyuproject.protostuff.ProtostuffIOUtil;
+import com.dyuproject.protostuff.runtime.RuntimeSchema;
+import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisPool;
+
 /**
  * Created by codingBoy on 17/2/17.
  */
 public class RedisDao {
+    private final JedisPool jedisPool;
+
+    public RedisDao(String ip, int port) {
+        jedisPool = new JedisPool(ip, port);
+    }
+
+    private RuntimeSchema<Seckill> schema = RuntimeSchema.createFrom(Seckill.class);
+
+
+    public Seckill getSeckill(long seckillId) {
+        //redis操作逻辑
+        try {
+            Jedis jedis = jedisPool.getResource();
+            try {
+                String key = "seckill:" + seckillId;
+                //并没有实现哪部序列化操作
+                //采用自定义序列化
+                //protostuff: pojo.
+                byte[] bytes = jedis.get(key.getBytes());
+                //缓存重获取到
+                if (bytes != null) {
+                    Seckill seckill=schema.newMessage();
+                    ProtostuffIOUtil.mergeFrom(bytes,seckill,schema);
+                    //seckill被反序列化
+
+                    return seckill;
+                }
+            }finally {
+                jedis.close();
+            }
+        }catch (Exception e) {
+
+        }
+        return null;
+    }
+
+    public String putSeckill(Seckill seckill) {
+        try {
+            Jedis jedis = jedisPool.getResource();
+            try {
+                String key = "seckill:" + seckill.getSeckillId();
+                byte[] bytes = ProtostuffIOUtil.toByteArray(seckill, schema,
+                        LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE));
+                //超时缓存
+                int timeout = 60 * 60;//1小时
+                String result = jedis.setex(key.getBytes(),timeout,bytes);
+
+                return result;
+            }finally {
+                jedis.close();
+            }
+        }catch (Exception e) {
+
+        }
+
+        return null;
+    }
 }

src/main/java/cn/codingxiaxw/service/impl/SeckillServiceImpl.java

@@ -2,6 +2,7 @@
 
 import cn.codingxiaxw.dao.SeckillDao;
 import cn.codingxiaxw.dao.SuccessKilledDao;
+import cn.codingxiaxw.dao.cache.RedisDao;
 import cn.codingxiaxw.dto.Exposer;
 import cn.codingxiaxw.dto.SeckillExecution;
 import cn.codingxiaxw.entity.Seckill;
@@ -42,6 +43,9 @@ public class SeckillServiceImpl implements SeckillService
     @Autowired //@Resource
     private SuccessKilledDao successKilledDao;
 
+    @Autowired
+    private RedisDao redisDao;
+
     public List<Seckill> getSeckillList() {
         return seckillDao.queryAll(0,4);
     }
@@ -51,12 +55,24 @@ public Seckill getById(long seckillId) {
     }
 
     public Exposer exportSeckillUrl(long seckillId) {
-        Seckill seckill=seckillDao.queryById(seckillId);
-        if (seckill==null) //说明查不到这个秒杀产品的记录
-        {
-            return new Exposer(false,seckillId);
+        //优化点:缓存优化:超时的基础上维护一致性
+        //1。访问redi
+
+
+        Seckill seckill = redisDao.getSeckill(seckillId);
+        if (seckill == null) {
+            //2.访问数据库
+            seckill = seckillDao.queryById(seckillId);
+            if (seckill == null) {//说明查不到这个秒杀产品的记录
+                return new Exposer(false, seckillId);
+            }else {
+                //3,放入redis
+                redisDao.putSeckill(seckill);
+            }
+
         }
 
+
         //若是秒杀未开启
         Date startTime=seckill.getStartTime();
         Date endTime=seckill.getEndTime();
@@ -98,26 +114,30 @@ public SeckillExecution executeSeckill(long seckillId, long userPhone, String md
         Date nowTime=new Date();
 
         try{
-            //减库存
-            int updateCount=seckillDao.reduceNumber(seckillId,nowTime);
-            if (updateCount<=0)
+
+            //否则更新了库存，秒杀成功,增加明细
+            int insertCount=successKilledDao.insertSuccessKilled(seckillId,userPhone);
+            //看是否该明细被重复插入，即用户是否重复秒杀
+            if (insertCount<=0)
             {
-                //没有更新库存记录，说明秒杀结束
-                throw new SeckillCloseException("seckill is closed");
+                throw new RepeatKillException("seckill repeated");
             }else {
-                //否则更新了库存，秒杀成功,增加明细
-                int insertCount=successKilledDao.insertSuccessKilled(seckillId,userPhone);
-                //看是否该明细被重复插入，即用户是否重复秒杀
-                if (insertCount<=0)
+
+                //减库存,热点商品竞争
+                int updateCount=seckillDao.reduceNumber(seckillId,nowTime);
+                if (updateCount<=0)
                 {
-                    throw new RepeatKillException("seckill repeated");
+                    //没有更新库存记录，说明秒杀结束 rollback
+                    throw new SeckillCloseException("seckill is closed");
                 }else {
-                    //秒杀成功,得到成功插入的明细记录,并返回成功秒杀的信息
+                    //秒杀成功,得到成功插入的明细记录,并返回成功秒杀的信息 commit
                     SuccessKilled successKilled=successKilledDao.queryByIdWithSeckill(seckillId,userPhone);
                     return new SeckillExecution(seckillId, SeckillStatEnum.SUCCESS,successKilled);
                 }
+
             }
 
+
         }catch (SeckillCloseException e1)
         {
             throw e1;

src/main/resources/spring/spring-dao.xml

@@ -54,7 +54,9 @@
         <property name="basePackage" value="cn.codingxiaxw.dao"/>
     </bean>
 
-
-
-
+    <!--redisDao-->
+    <bean id="redisDao" class="cn.codingxiaxw.dao.cache.RedisDao">
+        <constructor-arg index="0" value="localhost"/>
+        <constructor-arg index="1" value="6379"/>
+    </bean>
 </beans>

src/test/java/cn/codingxiaxw/dao/cache/RedisDaoTest.java

@@ -1,8 +1,45 @@
+package cn.codingxiaxw.dao.cache;
+
+import cn.codingxiaxw.dao.SeckillDao;
+import cn.codingxiaxw.entity.Seckill;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
 import static org.junit.Assert.*;
 
 /**
  * Created by codingBoy on 17/2/17.
  */
+@RunWith(SpringJUnit4ClassRunner.class)
+//告诉junit spring的配置文件
+@ContextConfiguration({"classpath:spring/spring-dao.xml"})
 public class RedisDaoTest {
 
+    private long id = 1001;
+
+    @Autowired
+    private RedisDao redisDao;
+
+    @Autowired
+    private SeckillDao seckillDao;
+
+    @Test
+    public void testSeckill() throws Exception {
+        //get and put
+
+        Seckill seckill = redisDao.getSeckill(id);
+        if (seckill == null) {
+            seckill = seckillDao.queryById(id);
+            if (seckill != null) {
+                String result = redisDao.putSeckill(seckill);
+                System.out.println(result);
+                seckill = redisDao.getSeckill(id);
+                System.out.println(seckill);
+            }
+        }
+    }
+
 }