zookeeper怎么实现分布式锁
2016-03-13 · 知道合伙人数码行家
huanglenzhi
知道合伙人数码行家
向TA提问 私信TA
这种实现非常简单,具体的流程如下
对应的实现如下
Java代码
package zk.lock;
import zk.util.NetworkUtil;
import zk.util.ZKUtil;
/**
* User: zhenghui
* Date: 14-3-26
* Time: 下午8:37
* 分布式锁实现.
*
* 这种实现的原理是,创建某一个任务的节点,比如 /lock/tasckname 然后获取对应的值,如果是当前的Ip,那么获得锁,如果不是,则没获得
* .如果该节点不存在,则创建该节点,并把改节点的值设置成当前的IP
*/
public class DistributedLock01 {
private ZKClient zkClient;
public static final String LOCK_ROOT = "/lock";
private String lockName;
public DistributedLock01(String connectString, int sessionTimeout,String lockName) throws Exception {
//先创建zk链接.
this.createConnection(connectString,sessionTimeout);
this.lockName = lockName;
}
public boolean tryLock(){
String path = ZKUtil.contact(LOCK_ROOT,lockName);
String localIp = NetworkUtil.getNetworkAddress();
try {
if(zkClient.exists(path)){
String ownnerIp = zkClient.getData(path);
if(localIp.equals(ownnerIp)){
return true;
}
} else {
zkClient.createPathIfAbsent(path,false);
if(zkClient.exists(path)){
String ownnerIp = zkClient.getData(path);
if(localIp.equals(ownnerIp)){
return true;
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
/**
* 创建zk连接
*
*/
protected void createConnection(String connectString, int sessionTimeout) throws Exception {
if(zkClient != null){
releaseConnection();
}
zkClient = new ZKClient(connectString,sessionTimeout);
zkClient.createPathIfAbsent(LOCK_ROOT,true);
}
/**
* 关闭ZK连接
*/
protected void releaseConnection() throws InterruptedException {
if (zkClient != null) {
zkClient.close();
}
}
}
