zookeeper订阅与发布实现

来源：互联网发布：mac 10.10.5 升级包编辑：程序博客网时间：2024/06/06 16:33

方式一：

import org.apache.curator.RetryPolicy;

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.CuratorFrameworkFactory.Builder;
import org.apache.curator.framework.api.BackgroundPathable;
import org.apache.curator.framework.api.CuratorWatcher;
import org.apache.curator.framework.recipes.cache.PathChildrenCache;
import org.apache.curator.framework.recipes.cache.PathChildrenCacheEvent;
import org.apache.curator.framework.recipes.cache.PathChildrenCacheListener;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.curator.utils.ZKPaths;
import org.apache.zookeeper.WatchedEvent;

public class CuratorWatch {
    static CuratorFramework zkclient = null;
    static String nameSpace = "mo";

    static {

        String zkhost = "10.144.5.218:2181";// zk的host
        RetryPolicy rp = new ExponentialBackoffRetry(1000, 3);// 重试机制
        Builder builder = CuratorFrameworkFactory.builder().connectString(zkhost)
                .connectionTimeoutMs(5000).sessionTimeoutMs(5000).retryPolicy(rp);
        builder.namespace(nameSpace);
        CuratorFramework zclient = builder.build();
        zkclient = zclient;
        zkclient.start();// 放在这前面执行
        zkclient.newNamespaceAwareEnsurePath("/" + nameSpace);

        CuratorWatcher callbackWatcher = new CuratorWatcher() {
            public void process(WatchedEvent event) throws Exception {

                //由于监听触发后即消失，若想持续监听，需要再次追加监听
                byte[] data = (byte[]) ((BackgroundPathable) zkclient.getData().usingWatcher(this))
                        .forPath("/mojianli");
                //TODO 具体业务逻辑
            }
        };

        try {
            //首次添加监听
            ((BackgroundPathable) zkclient.getData().usingWatcher(callbackWatcher))
                    .forPath("/mojianli");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    public static void main(String[] args) throws Exception {

        Thread.sleep(Long.MAX_VALUE);

}

｝

方式二：

import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.CuratorFrameworkFactory.Builder;
import org.apache.curator.framework.api.BackgroundPathable;
import org.apache.curator.framework.api.CuratorWatcher;
import org.apache.curator.framework.recipes.cache.PathChildrenCache;
import org.apache.curator.framework.recipes.cache.PathChildrenCacheEvent;
import org.apache.curator.framework.recipes.cache.PathChildrenCacheListener;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.curator.utils.ZKPaths;
import org.apache.zookeeper.WatchedEvent;

public class CuratorWatch {
    static CuratorFramework zkclient = null;
    static String nameSpace = "mo";

    static {

        String zkhost = "10.144.5.218:2181";// zk的host
        RetryPolicy rp = new ExponentialBackoffRetry(1000, 3);// 重试机制
        Builder builder = CuratorFrameworkFactory.builder().connectString(zkhost)
                .connectionTimeoutMs(5000).sessionTimeoutMs(5000).retryPolicy(rp);
        builder.namespace(nameSpace);
        CuratorFramework zclient = builder.build();
        zkclient = zclient;
        zkclient.start();// 放在这前面执行
        zkclient.newNamespaceAwareEnsurePath("/" + nameSpace);



    }

    public static void main(String[] args) throws Exception {

        watch();
        Thread.sleep(Long.MAX_VALUE);

    }

    /**
     *
     * 监听节点变化
     *
     */
    public static void watch() throws Exception {
        PathChildrenCache cache = new PathChildrenCache(zkclient, "/mo", false);
        cache.start();

        System.out.println("监听开始/zk........");
        PathChildrenCacheListener plis = new PathChildrenCacheListener() {

            @Override
            public void childEvent(CuratorFramework client, PathChildrenCacheEvent event)
                    throws Exception {
                switch (event.getType()) {
                    case CHILD_ADDED: {
                        System.out.println("Node added: "
                                + ZKPaths.getNodeFromPath(event.getData().getPath()));
                        break;
                    }

                    case CHILD_UPDATED: {
                        System.out.println("Node changed: "
                                + ZKPaths.getNodeFromPath(event.getData().getPath()));
                        break;
                    }

                    case CHILD_REMOVED: {
                        System.out.println("Node removed: "
                                + ZKPaths.getNodeFromPath(event.getData().getPath()));
                        break;
                    }
                }

            }
        };
        // 注册监听
        cache.getListenable().addListener(plis);

    }

}

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