zookeeper分布式集群中Curator的TreeCache监测节点数据更新添加删除

import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.cache.*;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.data.Stat;

import java.util.concurrent.TimeUnit;

public class Main {
    private final String TAG = "调试# ";

    public static void main(String[] args) {
        //初始化log4j，zookeeper否则报错。
        //org.apache.log4j.BasicConfigurator.configure();

        try {
            Main m = new Main();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private String getAddress() {
        String ip = "127.0.0.1";
        return ip + ":2181," + ip + ":2182," + ip + ":2183";
    }

    public Main() throws Exception {
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 5);
        CuratorFramework client = CuratorFrameworkFactory.builder()
                .connectString(getAddress())
                .sessionTimeoutMs(10 * 1000)
                .connectionTimeoutMs(20 * 1000)
                .retryPolicy(retryPolicy)
                .build();

        client.start();

        String path = "/test_data/my_path";

        //检测是否存在该路径。
        Stat stat = client.checkExists().forPath(path);

        //如果不存在这个路径，stat为null，创建新的节点路径。
        if (stat == null) {
            String s = client.create()
                    .creatingParentsIfNeeded()
                    .withMode(CreateMode.PERSISTENT)
                    .forPath(path);

            System.out.println(TAG + "已创建:" + s);
        } else {
            System.out.println(TAG + "已存在:" + path);
        }

        TreeCache treeCache = new TreeCache(client, path);
        TreeCacheListener treeCacheListener = new TreeCacheListener() {
            @Override
            public void childEvent(CuratorFramework client, TreeCacheEvent event) throws Exception {
                System.out.println("=============");
                System.out.println(TAG + "路径:" + event.getData().getPath());
                System.out.println(TAG + "数据:" + new String(event.getData().getData(), "UTF-8"));

                System.out.println(TAG + "ZooKeeper:" + client.getZookeeperClient().getZooKeeper().toString());
            }
        };

        treeCache.getListenable().addListener(treeCacheListener);
        treeCache.start();

        client.setData().forPath(path, "hello,world!".getBytes());
        TimeUnit.SECONDS.sleep(5);

        client.setData().forPath(path, "zhang phil".getBytes());
        TimeUnit.SECONDS.sleep(5);

        client.delete().deletingChildrenIfNeeded().forPath(path);
        TimeUnit.SECONDS.sleep(5);

        treeCache.close();
        client.close();

        System.out.println("结束");
    }
}

输出：

调试# 已创建:/test_data/my_path
=============
调试# 路径:/test_data/my_path
调试# 数据:172.17.238.45
调试# ZooKeeper:State:CONNECTED Timeout:10000 sessionid:0x300001d3a5a0014 local:/127.0.0.1:53720 remoteserver:127.0.0.1/127.0.0.1:2183 lastZxid:38654705956 xid:11 sent:11 recv:10 queuedpkts:0 pendingresp:1 queuedevents:0
=============
=============
调试# 路径:/test_data/my_path
调试# 数据:hello,world!
调试# ZooKeeper:State:CONNECTED Timeout:10000 sessionid:0x300001d3a5a0014 local:/127.0.0.1:53720 remoteserver:127.0.0.1/127.0.0.1:2183 lastZxid:38654705957 xid:12 sent:12 recv:13 queuedpkts:0 pendingresp:0 queuedevents:0
=============
调试# 路径:/test_data/my_path
调试# 数据:zhang phil
调试# ZooKeeper:State:CONNECTED Timeout:10000 sessionid:0x300001d3a5a0014 local:/127.0.0.1:53720 remoteserver:127.0.0.1/127.0.0.1:2183 lastZxid:38654705958 xid:14 sent:15 recv:17 queuedpkts:0 pendingresp:0 queuedevents:0
=============
调试# 路径:/test_data/my_path
调试# 数据:zhang phil
调试# ZooKeeper:State:CONNECTED Timeout:10000 sessionid:0x300001d3a5a0014 local:/127.0.0.1:53720 remoteserver:127.0.0.1/127.0.0.1:2183 lastZxid:38654705959 xid:15 sent:17 recv:20 queuedpkts:0 pendingresp:0 queuedevents:0
结束