1、首先搭載zookeeper集羣
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直接在這壓縮包解壓，
修改環境變量
vi /etc/profile 需要安裝jdk（同理直接解壓配置環境變量）
修改zoo_sample.cfg文件
cd /usr/local/zookeeper/conf
mv zoo_sample.cfg zoo.cfg
創建服務標識server.服務標識=hadoop*
.
--------------------------------------------
zkServer.sh start/stop/status
--------------------------------上述完成zookeeper集羣搭建---------------------------------------------------
【分佈式鎖】：在分佈式架構中，存在多個線程共享資源，=，就會引發線程安全問題；
如何解決線程安全，對共享資源進行加鎖。在分佈式中，是有數據庫分佈式鎖（影響性能）、redis分佈式鎖（不好判斷失效時間）
但是zookeeper有一個特點：臨時節點；並且有監聽節點狀態機制；恰恰剛好能解決資源共享問題；
一個線程獲取資源的時候獲取鎖除了完了再釋放鎖，就可以利用zookeeper寫
-------------------列子【生成訂單號、多線程下】-----------------------------
===============================OrderNumGenerator .java========================================
package com.zixue.lock;
import java.text.SimpleDateFormat;
import java.util.Date;
//生成訂單號規則
public class OrderNumGenerator {
private static int count = 0;
//生成訂單號規則方法
public String orderNumber() {
SimpleDateFormat simpt = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
return simpt.format(new Date()) + "-" + ++count;
}
}
===============================OrderService .java========================================
package com.zixue.lock;
//訂單服務
public class OrderService implements Runnable {
private OrderNumGenerator orderNumGenerator = new OrderNumGenerator();
private static Object oj = new Object();
private Lock lock=new ZookeeperDistrbuteLock();
public void run() {
getNumber();
}
public void getNumber() {
// synchronized (oj) {
lock.getLock();
String number = orderNumGenerator.orderNumber();
System.out.println(Thread.currentThread().getName() + ",生成訂單號:" + number);
lock.unLock();
}
public static void main(String[] args) {
for (int i = 0; i < 100; i++) {
new Thread(new OrderService()).start();
}
}
}
===============================Lock .java========================================
package com.zixue.lock;
public interface Lock {
//獲取到鎖的資源
public void getLock();
// 釋放鎖
public void unLock();
}
===============================ZookeeperAbstractLock .java========================================
package com.zixue.lock;
import org.I0Itec.zkclient.ZkClient;
//將重複的代碼,具體業務邏輯有子類去實現.
public abstract class ZookeeperAbstractLock implements Lock {
private static final String CONNECT_ADDRES = "192.168.1.103:2181,192.168.1.113:2181,192.168.1.114:2181";
protected ZkClient zkClient = new ZkClient(CONNECT_ADDRES);
protected static final String PATH = "/lock";
public void getLock() {
// tryLock() 創建zk臨時節點 如果創建成功返回true 否則返回false
if (tryLock()) {
System.out.println("獲取到鎖的資源 get lock");
} else {
// 等待
waitLock();
// 重寫獲取鎖的資源
getLock();
}
}
protected abstract boolean tryLock();
protected abstract void waitLock();
// 釋放鎖
public void unLock() {
if (zkClient != null) {
zkClient.close();
}
System.out.println("釋放鎖的資源..");
}
}
===============================ZookeeperDistrbuteLock .java========================================
package com.zixue.lock;
import java.util.concurrent.CountDownLatch;
import org.I0Itec.zkclient.IZkDataListener;
public class ZookeeperDistrbuteLock extends ZookeeperAbstractLock {
private CountDownLatch countDownLatch = null;
@Override
protected boolean tryLock() {
try {
zkClient.createEphemeral(PATH);
return true;
} catch (Exception e) {
//e.printStackTrace();
return false;
}
}
@Override
protected void waitLock() {
IZkDataListener zkDataListener = new IZkDataListener() {
// 節點被刪除的時候 事件通知
public void handleDataDeleted(String path) throws Exception {
// 喚醒被等待的線程
if (countDownLatch != null) {
countDownLatch.countDown();
System.out.println("刪除節點.....");
}
}
public void handleDataChange(String path, Object data) throws Exception {
}
};
// 註冊到zkclient進行監聽
zkClient.subscribeDataChanges(PATH, zkDataListener);
if (zkClient.exists(PATH)) {
countDownLatch = new CountDownLatch(1);
try {
countDownLatch.await();
} catch (Exception e) {
// TODO: handle exception
}
}
// 刪除監聽
zkClient.unsubscribeDataChanges(PATH, zkDataListener);
}
}
==================pom.xml===============
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>zixue.com</groupId>
<artifactId>spring-cloud-zookeeper</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>spring-cloud-zookeeper</name>
<url>http://maven.apache.org</url>
<parent>
<groupId>com.zixue</groupId>
<artifactId>shopmall-parent</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<dependencies>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.6</version>
</dependency>
<dependency>
<groupId>com.101tec</groupId>
<artifactId>zkclient</artifactId>
<version>0.10</version>
</dependency>
</dependencies>
</project>