Java 客户端

• pom.xml 文件中引入相关api

 <dependency>      <groupId>org.apache.zookeeper</groupId>      <artifactId>zookeeper</artifactId>      <version>3.5.4-beta</version></dependency>

• 创建连接

/** * 创建 zookeeper 会话 * <p> * <p> * zookeeper 客户端 和 服务端创建会话的过程是异步的。也就是客户度通过构造方法创建会话后立即返回，此时的连接并没有完全建立。 * 当真正的会话建立完成后，zk服务端会给客户端通知一个事件，客户端获取通知之后在表明连接正在建立。 */public class ZooKeeperClientSession implements Watcher {    //用于等待zk服务端通知    private static CountDownLatch latch = new CountDownLatch(1);    public static void main(String[] args) throws Exception {        ZooKeeper zooKeeper = new ZooKeeper("127.0.0.1:2183", 5000, new ZooKeeperClientSession());        System.out.println(zooKeeper.getState());        latch.await();        long sessionId = zooKeeper.getSessionId();        byte[] sessionPasswd = zooKeeper.getSessionPasswd();        System.out.println(zooKeeper.getSessionId());        /**         *  利用 sessionId 和 sessionPasswd 复用会话连接         */        ZooKeeper zooKeeper1 = new ZooKeeper("127.0.0.1:2183",                5000,                new ZooKeeperClientSession(),                sessionId,                sessionPasswd);        System.out.println(zooKeeper1.getSessionId());    }    /**     * 处理 zookeeper 服务端的 Watcher 通知     * @param watchedEvent     */    public void process(WatchedEvent watchedEvent) {        System.out.println("receive watch event : " + watchedEvent);        if (Event.KeeperState.SyncConnected == watchedEvent.getState()) {            latch.countDown();        }    }}

1.构造函数说明

ZooKeeper(String connectString, int sessionTimeout, Watcher watcher)ZooKeeper(String connectString,           int sessionTimeout,           Watcher watcher,          boolean canBeReadOnly)ZooKeeper(String connectString,          int sessionTimeout,           Watcher watcher,           long sessionId,           byte[] sessionPasswd)ZooKeeper(String connectString,           int sessionTimeout,           Watcher watcher,          long sessionId,           byte[] sessionPasswd,           boolean canBeReadOnly)

• 创建节点