一,前言
實踐是檢驗真理的唯一標準,紙上得來終覺淺嘛!想認識一個人,光靠個人資料怎麼行,哪怕見面聊上那麼一兩句,那也是會產生很多偶然性的結果,俗話說,患難見真情,當然,此處不是讓你去患難,而是和redis進行一個簡單的交互,那其中機理雖不說詳識,但大致什麼樣子和總體印象還是會有的。話不多說,擼起袖子就是幹!
二,具體操作
1,打開eclipse,新建Maven工程,
2,額外導入jar包:
<!-- redis工具包 -->
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>3.0.1</version>
</dependency>
3,代碼不多,就兩個類
(1)MyRedisTest.java
package com.spring.server.redis;
import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import redis.clients.jedis.Jedis;
public class MyRedisTest {
public static void main(String args[]){
final String watchKeys = "watchKeys";
ExecutorService executor = Executors.newFixedThreadPool(20);//20個線程池併發。
final Jedis jedis = new Jedis("127.0.0.1",6379);
System.out.println(jedis.get("myKey"));
jedis.set(watchKeys,"100");//設置起始的搶購數。
jedis.close();
for(int i = 0; i < 1000; i++){//設置1000個人來發起搶購
executor.execute(new MyRunnable("user"+getRandomString(6)));
}
executor.shutdown();
}
private static String getRandomString(int length) {//length是隨機字符串長度
String base = "abcdefghijklmnopqrstuvwxyz0123456789";
Random random = new Random();
StringBuffer sb = new StringBuffer();
for(int i = 0; i<length; i++){
//該方法的作用是生成一個隨機的int值,該值介於[0,n)的區間,也就是0到n之間的隨機int值,包含0而不包含n。
int number = random.nextInt(base.length());
//charAt() 方法用於返回指定索引處的字符。索引範圍爲從 0 到 length() - 1。
sb.append(base.charAt(number));
}
return sb.toString();
}
}
(2)MyRunnable.java
package com.spring.server.redis;
import java.util.List;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.Transaction;
public class MyRunnable implements Runnable {
String watchKeys = "watchKeys";//監視keys
Jedis jedis = new Jedis("127.0.0.1",6379);
String userInfo;
public void myRunnable(){
}
public MyRunnable(String uinfo){
this.userInfo = uinfo;
}
@Override
public void run() {
try{
jedis.watch(watchKeys);
String val = jedis.get(watchKeys);
int valint = Integer.valueOf(val);
if(valint <= 100 && valint >=1){
Transaction tx = jedis.multi();//開啓事務
tx.incrBy("watchKeys",-1);
List<Object> list = tx.exec();//提交事務,如果此時watchKeys被改動了,則返回null
if(list == null || list.size()==0){
String failuserifo = "fail"+userInfo;
String failinfo="用戶:" + failuserifo + "商品爭搶失敗,搶購失敗";
System.out.println(failinfo);
/* 搶購失敗業務邏輯 */
jedis.setnx(failuserifo, failinfo);
}else{
for(Object succ : list){
String succuserifo ="succ"+succ.toString() +userInfo ;
String succinfo="用戶:" + succuserifo + "搶購成功,當前搶購成功人數:"
+ (1-(valint-100));
System.out.println(succinfo);
/* 搶購成功業務邏輯 */
jedis.setnx(succuserifo, succinfo);
}
}
}else{
String failuserifo = "kcfail" + userInfo;
String failinfo1="用戶:" + failuserifo + "商品被搶購完畢,搶購失敗";
System.out.println(failinfo1);
jedis.setnx(failuserifo, failinfo1);
// Thread.sleep(500);
return;
}
}catch(Exception e){
e.printStackTrace();
}finally{
jedis.close();
}
}
}
4,點擊運行
OK! 到這,與redis的互動結束了,你有什麼收穫呢?