public class SimpleZkClient {

    private static final String connectString = "mini1:2181,mini2:2181,mini3:2181";

    private static final int sessionTimeout = 2000;

    ZooKeeper zkClient = null;

    @Before

    public void init() throws Exception {

        zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {

            @Override

            public void process(WatchedEvent event) {

                // 收到事件通知后的回调函数（应该是我们自己的事件处理逻辑）

                System.out.println(event.getType() + "---" + event.getPath());

                try {

                    zkClient.getChildren("/", true);

                } catch (Exception e) {

                }

            }

        });

    }

    /**

     * 数据的增删改查

     */

    // 创建数据节点到zk中

    public void testCreate() throws KeeperException, InterruptedException {

        // 参数1：要创建的节点的路径 参数2：节点大数据 参数3：节点的权限 参数4：节点的类型

        String nodeCreated = zkClient.create("/eclipse", "hellozk".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);

        //上传的数据可以是任何类型，但都要转成byte[]

    }

    //判断znode是否存在

    @Test

    public void testExist() throws Exception{

        Stat stat = zkClient.exists("/eclipse", false);

        System.out.println(stat==null?"not exist":"exist");

    }

    // 获取子节点

    @Test

    public void getChildren() throws Exception {

        List<String> children = zkClient.getChildren("/", true);

        for (String child : children) {

            System.out.println(child);

        }

        Thread.sleep(Long.MAX_VALUE);

    }

    //获取znode的数据

    @Test

    public void getData() throws Exception {

        byte[] data = zkClient.getData("/eclipse", false, null);

        System.out.println(new String(data));

    }

    //删除znode

    @Test

    public void deleteZnode() throws Exception {

        //参数2：指定要删除的版本，-1表示删除所有版本

        zkClient.delete("/eclipse", -1);

    }

    //删除znode

    @Test

    public void setData() throws Exception {

        zkClient.setData("/app1", "imissyou angelababy".getBytes(), -1);

        byte[] data = zkClient.getData("/app1", false, null);

        System.out.println(new String(data));

    }

}