ZooKeeper Curator分散式鎖 - 使用樣例：模擬12306售票

匯入座標 外掛

<dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
            <scope>test</scope>
        </dependency>

        <!--curator-->
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-framework</artifactId>
            <version>4.0.0</version>
        </dependency>

        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-recipes</artifactId>
            <version>4.0.0</version>
        </dependency>
        <!--日誌-->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.21</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.21</version>
        </dependency>




		<plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
 

執行緒任務(買票服務) - Ticket12306

package com.itheima.curator;

import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;
import org.apache.curator.retry.ExponentialBackoffRetry;

import java.util.concurrent.TimeUnit;

public class Ticket12306 implements Runnable{

    private int tickets = 10;//資料庫的票數

    private InterProcessMutex lock ;


    public Ticket12306(){
        //重試策略
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(3000, 10);
        //2.第二種方式
        //CuratorFrameworkFactory.builder();
        CuratorFramework client = CuratorFrameworkFactory.builder()
                .connectString("192.168.149.135:2181")
                .sessionTimeoutMs(60 * 1000)
                .connectionTimeoutMs(15 * 1000)
                .retryPolicy(retryPolicy)
                .build();

        //開啟連線
        client.start();

        lock = new InterProcessMutex(client,"/lock");
    }

    @Override
    public void run() {

        while(true){
            //獲取鎖
            try {
                lock.acquire(3, TimeUnit.SECONDS);
                if(tickets > 0){

                    System.out.println(Thread.currentThread()+":"+tickets);
                    Thread.sleep(100);
                    tickets--;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }finally {
                //釋放鎖
                try {
                    lock.release();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

 

LockTest

package com.itheima.curator;

public class LockTest {


    public static void main(String[] args) {
        Ticket12306 ticket12306 = new Ticket12306();

        //建立客戶端
        Thread t1 = new Thread(ticket12306,"攜程");
        Thread t2 = new Thread(ticket12306,"飛豬");

        t1.start();
        t2.start();
    }

}