Apache Curator Node Cache Watcher

只能监听某一路径本身的add,delete,update

1.run NodeListener

2.run NLTest

package com.collonn.javaUtilMvn.zookeeper.curator.NodeCache;

public class NLTest {
    public static void main(String[] args) throws Exception {
        NLClientCreate.main(null);
        Thread.sleep(1000 * 2);
        NLClientUpdate.main(null);
        Thread.sleep(1000 * 2);
        NLClientDelete.main(null);
    }
}

package com.collonn.javaUtilMvn.zookeeper.curator.NodeCache;

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.curator.utils.EnsurePath;

import java.util.List;

public class NodeListener {
    public static final String C_PATH = "/TestNode";
    public static final String CHARSET = "UTF-8";

    public static void main(String[] args) {
        try {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try{
                        String zookeeperConnectionString = "127.0.0.1:2181";
                        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
                        CuratorFramework client = CuratorFrameworkFactory.newClient(zookeeperConnectionString, retryPolicy);
                        client.start();

                        final NodeCache nodeCache = new NodeCache(client, C_PATH);
                        nodeCache.getListenable().addListener(new NodeCacheListener() {
                            @Override
                            public void nodeChanged() throws Exception {
                                System.out.println("================== catch node data change ==================");
                                ChildData childData = nodeCache.getCurrentData();
                                if(childData == null){
                                    System.out.println("===delete, path=" + C_PATH + ", childData=" + childData);
                                }else{
                                    System.out.println("===update or add, path=" + C_PATH + ", childData=" + new String(childData.getData(), CHARSET));
                                }
                            }
                        });
                        nodeCache.start();

                        Thread.sleep(Integer.MAX_VALUE);
                        client.close();
                    }catch (Exception e){
                        e.printStackTrace();
                    }
                }
            }).start();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}

package com.collonn.javaUtilMvn.zookeeper.curator.NodeCache;

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

import java.util.Random;

public class NLClientCreate {
    public static void main(String[] args) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    String zookeeperConnectionString = "127.0.0.1:2181";
                    RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
                    CuratorFramework client = CuratorFrameworkFactory.newClient(zookeeperConnectionString, retryPolicy);
                    client.start();

                    Stat stat = client.checkExists().forPath(NodeListener.C_PATH);
                    if (stat == null) {
                        client.create().withMode(CreateMode.PERSISTENT).forPath(NodeListener.C_PATH, "-1".getBytes(NodeListener.CHARSET));
                    }

                    client.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

package com.collonn.javaUtilMvn.zookeeper.curator.NodeCache;

import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.data.Stat;

import java.util.Random;

public class NLClientUpdate {
    public static void main(String[] args) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    String zookeeperConnectionString = "127.0.0.1:2181";
                    RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
                    CuratorFramework client = CuratorFrameworkFactory.newClient(zookeeperConnectionString, retryPolicy);
                    client.start();

                    Stat stat = client.checkExists().forPath(NodeListener.C_PATH);
                    if (stat != null) {
                        client.setData().forPath(NodeListener.C_PATH, "128".getBytes(NodeListener.CHARSET));
                    }

                    client.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

package com.collonn.javaUtilMvn.zookeeper.curator.NodeCache;

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

import java.util.Random;

public class NLClientDelete {
    public static void main(String[] args) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    String zookeeperConnectionString = "127.0.0.1:2181";
                    RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
                    CuratorFramework client = CuratorFrameworkFactory.newClient(zookeeperConnectionString, retryPolicy);
                    client.start();

                    Stat stat = client.checkExists().forPath(NodeListener.C_PATH);
                    if (stat != null) {
                        client.delete().forPath(NodeListener.C_PATH);
                    }

                    client.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}