可以利用redis的事务加上watch监听方法,具体代码如下!
1 package com.github.distribute.lock.redis; 2 3 import java.util.List; 4 import java.util.Set; 5 import java.util.concurrent.ExecutorService; 6 import java.util.concurrent.Executors; 7 8 import redis.clients.jedis.Jedis; 9 import redis.clients.jedis.Transaction; 10 11 /** 12 * redis乐观锁实例 13 * @author linbingwen 14 * 15 */ 16 public class OptimisticLockTest { 17 18 public static void main(String[] args) throws InterruptedException { 19 long starTime=System.currentTimeMillis(); 20 21 initPrduct(); 22 initClient(); 23 printResult(); 24 25 long endTime=System.currentTimeMillis(); 26 long Time=endTime-starTime; 27 System.out.println("程序运行时间： "+Time+"ms"); 28 29 } 30 31 /** 32 * 输出结果 33 */ 34 public static void printResult() { 35 Jedis jedis = RedisUtil.getInstance().getJedis(); 36 Set<String> set = jedis.smembers("clientList"); 37 38 int i = 1; 39 for (String value : set) { 40 System.out.println("第" + i++ + "个抢到商品，"+value + " "); 41 } 42 43 RedisUtil.returnResource(jedis); 44 } 45 46 /* 47 * 初始化顾客开始抢商品 48 */ 49 public static void initClient() { 50 ExecutorService cachedThreadPool = Executors.newCachedThreadPool(); 51 int clientNum = 10000;// 模拟客户数目 52 for (int i = 0; i < clientNum; i++) { 53 cachedThreadPool.execute(new ClientThread(i)); 54 } 55 cachedThreadPool.shutdown(); 56 57 while(true){ 58 if(cachedThreadPool.isTerminated()){ 59 System.out.println("所有的线程都结束了！"); 60 break; 61 } 62 try { 63 Thread.sleep(1000); 64 } catch (InterruptedException e) { 65 e.printStackTrace(); 66 } 67 } 68 } 69 70 /** 71 * 初始化商品个数 72 */ 73 public static void initPrduct() { 74 int prdNum = 100;// 商品个数 75 String key = "prdNum_100001"; 76 String clientList = "clientList";// 抢购到商品的顾客列表 77 Jedis jedis = RedisUtil.getInstance().getJedis(); 78 79 if (jedis.exists(key)) { 80 jedis.del(key); 81 } 82 83 if (jedis.exists(clientList)) { 84 jedis.del(clientList); 85 } 86 87 jedis.set(key, String.valueOf(prdNum));// 初始化 88 RedisUtil.returnResource(jedis); 89 } 90 91 } 92 93 /** 94 * 顾客线程 95 * 96 * @author linbingwen 97 * 98 */ 99 class ClientThread implements Runnable { 100 Jedis jedis = null; 101 String key = "prdNum_10001";// 商品主键 102 String clientList = "clientList";//// 抢购到商品的顾客列表主键 103 String clientName; 104 105 public ClientThread(int num) { 106 clientName = "编号=" + num; 107 } 108 109 public void run() { 110 try { 111 Thread.sleep((int)(Math.random()*5000));// 随机睡眠一下 112 } catch (InterruptedException e1) { 113 } 114 while (true) { 115 System.out.println("顾客:" + clientName + "开始抢商品"); 116 jedis = RedisUtil.getInstance().getJedis(); 117 try { 118 jedis.watch(key); 119 int prdNum = Integer.parseInt(jedis.get(key));// 当前商品个数 120 if (prdNum > 0) { 121 Transaction transaction = jedis.multi(); 122 transaction.set(key, String.valueOf(prdNum - 1)); 123 List<Object> result = transaction.exec(); 124 if (result == null || result.isEmpty()) { 125 System.out.println("悲剧了，顾客:" + clientName + "没有抢到商品");// 可能是watch-key被外部修改，或者是数据操作被驳回 126 } else { 127 jedis.sadd(clientList, clientName);// 抢到商品记录一下 128 System.out.println("好高兴，顾客:" + clientName + "抢到商品"); 129 break; 130 } 131 } else { 132 System.out.println("悲剧了，库存为0，顾客:" + clientName + "没有抢到商品"); 133 break; 134 } 135 } catch (Exception e) { 136 e.printStackTrace(); 137 } finally { 138 jedis.unwatch(); 139 RedisUtil.returnResource(jedis); 140 } 141 142 } 143 } 144 145 }