初步认识zookeeper（3）--JavaAPI操作节点（增删改查）

目录概要

• 初始化连接
• 增加节点
• 查询节点
• 修改节点
• 删除节点

直接干代码，引入pom依赖

<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.10</version>
</dependency>

1、初始化zookeeper连接

final CountDownLatch countDownLatch = new CountDownLatch(1);
//若是集群的话，用,号隔开如:192.168.137.128:2181,192.168.137.129:2181,192.168.137.130:2181
ZooKeeper zooKeeper = new ZooKeeper("192.168.137.128:2181"
, 4000, new Watcher() {
@Override
public void process(WatchedEvent watchedEvent) {
System.out.println("事件："+watchedEvent.getType());
//连接成功
if (watchedEvent.getState() == Event.KeeperState.SyncConnected) {
countDownLatch.countDown();
}
}
});
System.out.println("1"+zooKeeper.getState());
countDownLatch.await();
System.out.println(zooKeeper.getState());

结果如下：

2、增加节点

zooKeeper.create("/ws","gg".getBytes(),
ZooDefs.Ids.OPEN_ACL_UNSAFE,
CreateMode.PERSISTENT);//CreateMode.PERSISTENT持久化

参数说明：

3、查询节点

//查询节点
Stat stat = new Stat();
byte[] bye = zooKeeper.getData("/ws",true,stat);
System.out.println("查询出的节点内容：" +new String(bye));

注意:stat中包含节点的版本信息，修改或删除时需要版本信息

4、修改节点

//修改节点
stat = zooKeeper.setData("/ws","gg2".getBytes(), stat.getVersion());

5、删除节点

//删除节点
zooKeeper.delete("/ws",stat.getVersion());

6、最后关闭zookeeper连接

zooKeeper.close();