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Curator实现zookeeper的节点监听详解

作者：暴躁的程序猿啊

这篇文章主要介绍了Curator实现zookeeper的节点监听详解,Curtor框架中一共有三个实现监听的方式,一种是NodeCache监听指定节点,一种是pathChildrenCache监听子节点,一种是TreeCache可以监控所有节点 相当于以上两种的合集,需要的朋友可以参考下

Curator实现zookeeper的节点监听

Curtor框架中一共有三个实现监听的方式 一种是NodeCache监听指定节点 一种是pathChildrenCache监听子节点 一种是TreeCache可以监控所有节点 相当于以上两种的合集

引入依赖

        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-framework</artifactId>
            <version>4.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-client</artifactId>
            <version>4.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-recipes</artifactId>
            <version>4.3.0</version>
        </dependency>

创建一个测试类 连接好客户端

public class CuratorTest {
    private CuratorFramework curatorFramework;
    @Before
    public void testCreate() {
        ExponentialBackoffRetry retry = new ExponentialBackoffRetry(2, 10);
        curatorFramework = CuratorFrameworkFactory.builder()
                .connectString("127.0.0.1:2181")
                .connectionTimeoutMs(60 * 1000)
                .sessionTimeoutMs(15 * 10000)
                .retryPolicy(retry).build();
        curatorFramework.start();
    }
   @After
    public void close() {
        if (curatorFramework != null) {
            curatorFramework.close();
        }
    }
}

Watch监听之NodeCache

监听一个指定节点

 @Test
    public void testUpdate() throws Exception {
        //监听一个节点
        NodeCache nodeCache = new NodeCache(curatorFramework,"/dongwuyuan");
        //注册监听
        nodeCache.getListenable().addListener(new NodeCacheListener() {
            @Override
            public void nodeChanged() throws Exception {
                System.out.println("节点变化了！！！！");
            }
        });
        //开启监听 参数 如果设置为true 则开启监听时加载缓存数据
        nodeCache.start(true);
        while (true){
        }
    }
set /dongwuyuan "laohu"

在这里插入图片描述

Watch监听之PathChildrenCache

监听子节点的变化

 @Test
    public void testPathChildrenCache() throws Exception {
        // 参数  客户端，路径 ，缓存数据，是否压缩，线程池
        PathChildrenCache pathChildrenCache = new PathChildrenCache(curatorFramework,"/dongwuyuan",true);
        //绑定监听器
        pathChildrenCache.getListenable().addListener(new PathChildrenCacheListener() {
            @Override
            public void childEvent(CuratorFramework curatorFramework, PathChildrenCacheEvent pathChildrenCacheEvent) throws Exception {
                System.out.println("子节点变化了");
                System.out.println(pathChildrenCacheEvent);
                //监听子节点的变更,并且拿到变更后的数据
                PathChildrenCacheEvent.Type type = pathChildrenCacheEvent.getType();
                //判断类型是否是update
                if(type.equals(PathChildrenCacheEvent.Type.CHILD_UPDATED)){
                     //拿到数据
                    byte[] data = pathChildrenCacheEvent.getData().getData();
                    System.out.println(data);
                }
            }
        });
        //开启监听
        pathChildrenCache.start();
        while (true){
        }
    }

watch监听之TreeCache

  /**
     * TreeCache:监听节点自己和所有子节点们
     */
    @Test
    public void testTreeCache(){
        //1.创建监听器
        TreeCache treeCache = new TreeCache(curatorFramework, "/dongwuyuan");
        //2.注册监听
        treeCache.getListenable().addListener(new TreeCacheListener() {
            @Override
            public void childEvent(CuratorFramework client, TreeCacheEvent event) throws Exception {
                System.out.println("节点变化了");
                System.out.println(event);
            }
        });
        //开启监听
        try {
            treeCache.start();
            while (true){
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
[zk: localhost:2181(CONNECTED) 13] delete /dongwuyuan/node1

在这里插入图片描述

[zk: localhost:2181(CONNECTED) 15] set /dongwuyuan/node2  "shizi"

在这里插入图片描述

完整代码

public class CuratorTest {
    private CuratorFramework curatorFramework;
    @Before
    public void testCreate() {
        ExponentialBackoffRetry retry = new ExponentialBackoffRetry(2, 10);
        curatorFramework = CuratorFrameworkFactory.builder()
                .connectString("127.0.0.1:2181")
                .connectionTimeoutMs(60 * 1000)
                .sessionTimeoutMs(15 * 10000)
                .retryPolicy(retry).build();
        curatorFramework.start();
    }
    @Test
    public void testUpdate() throws Exception {
        //监听一个节点
        NodeCache nodeCache = new NodeCache(curatorFramework,"/dongwuyuan");
        //注册监听
        nodeCache.getListenable().addListener(new NodeCacheListener() {
            @Override
            public void nodeChanged() throws Exception {
                System.out.println("节点变化了！！！！");
            }
        });
        //开启监听 参数 如果设置为true 则开启监听时加载缓存数据
        nodeCache.start(true);
        while (true){
        }
    }
    @Test
    public void testPathChildrenCache() throws Exception {
        // 参数  客户端，路径 ，缓存数据，是否压缩，线程池
        PathChildrenCache pathChildrenCache = new PathChildrenCache(curatorFramework,"/dongwuyuan",true);
        //绑定监听器
        pathChildrenCache.getListenable().addListener(new PathChildrenCacheListener() {
            @Override
            public void childEvent(CuratorFramework curatorFramework, PathChildrenCacheEvent pathChildrenCacheEvent) throws Exception {
                System.out.println("子节点变化了");
                System.out.println(pathChildrenCacheEvent);
                //监听子节点的变更,并且拿到变更后的数据
                PathChildrenCacheEvent.Type type = pathChildrenCacheEvent.getType();
                //判断类型是否是update
                if(type.equals(PathChildrenCacheEvent.Type.CHILD_UPDATED)){
                     //拿到数据
                    byte[] data = pathChildrenCacheEvent.getData().getData();
                    System.out.println(data);
                }
            }
        });
        //开启监听
        pathChildrenCache.start();
        while (true){
        }
    }
    /**
     * TreeCache:监听节点自己和所有子节点们
     */
    @Test
    public void testTreeCache(){
        //1.创建监听器
        TreeCache treeCache = new TreeCache(curatorFramework, "/dongwuyuan");
        //2.注册监听
        treeCache.getListenable().addListener(new TreeCacheListener() {
            @Override
            public void childEvent(CuratorFramework client, TreeCacheEvent event) throws Exception {
                System.out.println("节点变化了");
                System.out.println(event);
            }
        });
        //开启监听
        try {
            treeCache.start();
            while (true){
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    @After
    public void close() {
        if (curatorFramework != null) {
            curatorFramework.close();
        }
    }
}

到此这篇关于Curator实现zookeeper的节点监听详解的文章就介绍到这了,更多相关zookeeper节点监听内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！

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