java客户端测试连接zookeeper服务器

连接下zookeeper服务器，判断是否连接成功。

下面有些额外代码，是因为不加上的话会报错，错误日志是：

Exception in thread "main" org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /

网上很多都说是linux服务器没关闭防火墙，但我关闭了防火墙还是照样报错。

public class SimpleZkClient {public static void waitUntilConnected(ZooKeeper testZooKeeper, CountDownLatch testLatch) {        if(testZooKeeper.getState() == States.CONNECTING) {            try {                testLatch.await();            } catch (InterruptedException err) {                System.out.println("Latch exception");            }        }    } static class ConnectedWatcher implements Watcher {        private CountDownLatch connectedLatch;        ConnectedWatcher(CountDownLatch connectedLatch) {            this.connectedLatch = connectedLatch;  /* CountDownLatch实例初始化时设为1即可 */        }        /** * zookeeper服务集群监听到某个指定数据节点上发生的事件后，会通知监听注册者（客户端）， * 然后客户端就会调用process方法，并将接收到的事件event作为参数传递给process方法 */        @Override        public void process(WatchedEvent event) {            if (event.getState() == KeeperState.SyncConnected) {                connectedLatch.countDown(); /* ZK连接成功时，计数器由1减为0 */            }            System.out.println("节点:" + event.getPath() + " 发生了事件：" + event.getType());        }    }public static void main(String[] args) throws Exception {CountDownLatch sampleLatch = new CountDownLatch(1);Watcher sampleWatcher = new ConnectedWatcher (sampleLatch);/* * 创建一个zookeeper的java客户端 * 三个参数分别是： * connectString ：zk服务器地址 * sessionTimeout：连接超时阈值 * watcher：监听器 */ZooKeeper zkCli = new ZooKeeper("192.168.77.70:2181,192.168.77.80:2181", 2000, sampleWatcher);/* 只有当zkCli链接成功（状态为 SyncConnected)时，此函数调用才结束 */ waitUntilConnected(zkCli, sampleLatch);         /*接下来就可以继续zkCli访问了，避免因为zkCli未连接成功时的访问出错 */ // 获取"/"节点下的子节点列表，并对"/"节点注册监听器List<String> children = zkCli.getChildren("/", true);for (String child : children) {System.out.println(child);}zkCli.close();}}

结果：