高并发是如淘宝等一些大型项目不可避免的实现功能，否则数据会冲垮一切，那么在redis中如何实现高并发呢?这次就来看看吧。
实例
新建一个项目，首先引入JAVA中redis操作库：Jedis，这里使用的是jedis-2.9.0.jar
创建一个类MyRedistest.class做线程操作
package com.myredistest;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import redis.clients.jedis.Jedis;
/**
* redis
*
* @author 10255_000
*
*/
public class MyRedistest
{
public static void main(String[] args)
{
final String watchkeys = "watchkeys";
ExecutorService executor = Executors.newFixedThreadPool(20); //20个线程池并发数
final Jedis jedis = new Jedis("192.168.56.101", 6379);
jedis.set(watchkeys, "100"); //设置起始的抢购数
// jedis.del("setsucc", "setfail");
jedis.close();
for (int i = 0; i < 1000; i++)
{ //设置1000个人来发起抢购
executor.execute(new MyRunnable("user" + getRandomString(6)));
}
executor.shutdown();
}
public static String getRandomString(int length)
{ //length是随机字符串长度
String base = "abcdefghijklmnopqrstuvwxyz0123456789";
Random random = new Random();
StringBuffer sb = new StringBuffer();
for (int i = 0; i < length; i++)
{
int number = random.nextInt(base.length());
sb.append(base.charAt(number));
}
return sb.toString();
}
}再建一个类MyRunnable.class 实现Runnable做线程操作
package com.myredistest;
import java.util.List;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.Transaction;
public class MyRunnable implements Runnable
{
String watchkeys = "watchkeys"; // 监视keys
Jedis jedis = new Jedis("192.168.56.101", 6379);
String userinfo;
public MyRunnable()
{}
public MyRunnable(String uinfo)
{
this.userinfo = uinfo;
}
@Override
public void run()
{
try
{
jedis.watch(watchkeys); // watchkeys
String val = jedis.get(watchkeys);
int valint = Integer.valueOf(val);
if (valint <= 100 && valint >= 1)
{
Transaction tx = jedis.multi(); // 开启事务
// tx.incr("watchkeys");
tx.incrBy("watchkeys", -1);
List < Object > list = tx.exec(); // 提交事务，如果此时watchkeys被改动了，则返回null
if (list == null || list.size() == 0)
{
String failuserifo = "fail" + userinfo;
String failinfo = "用户：" + failuserifo + "商品争抢失败，抢购失败";
System.out.println(failinfo);
/* 抢购失败业务逻辑 */
jedis.setnx(failuserifo, failinfo);
}
else
{
for (Object succ: list)
{
String succuserifo = "succ" + succ.toString() + userinfo;
String succinfo = "用户：" + succuserifo + "抢购成功，当前抢购成功人数:" +
(1 - (valint - 100));
System.out.println(succinfo);
/* 抢购成功业务逻辑 */
jedis.setnx(succuserifo, succinfo);
}
}
}
else
{
String failuserifo = "kcfail" + userinfo;
String failinfo1 = "用户：" + failuserifo + "商品被抢购完毕，抢购失败";
System.out.println(failinfo1);
jedis.setnx(failuserifo, failinfo1);
// Thread.sleep(500);
return;
}
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
jedis.close();
}
}
}最后启动MyRedistest，基于redis队列实现高并发就完成了。
以上就是今天的全部内容，掌握高并发是一名程序员进阶的必然功能，如果还有想了解的java常见问题及解决方法，欢迎来奇Q工具网了解详情。
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