【Java】Zookeeper的Java客户端Api操作

Zookeeper的使用版本

3.4.9

这里使用的Java客户端框架是curator，以下是对应版本的依赖。

<!--测试包-->
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
</dependency>
<!--curator 两个必须依赖包  zookeeper客户端-->
<dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-framework</artifactId>
    <version>2.12.0</version>
</dependency>

<dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-recipes</artifactId>
    <version>2.12.0</version>
</dependency>

操作代码

   //创建节点
    @Test
    public void createZNode() throws Exception {
        //1.2 得到客户端
        CuratorFramework client =getClient();
        //3.启动客户端
        client.start();
        //4.创建节点
        client.create().creatingParentContainersIfNeeded().withMode(CreateMode.PERSISTENT).forPath("/client", "zhangsan".getBytes());
        //5.关闭客户端
        client.close();
    }

    //修改节点
    @Test
    public void updateZNode() throws Exception {
        //1.2 得到客户端
        CuratorFramework client = getClient();
        //3.启动客户端
        client.start();
        //4.修改节点
        client.setData().forPath("/client", "lisi".getBytes());
        //5.关闭客户端
        client.close();
    }

    //查询节点
    @Test
    public void queryZNode() throws Exception {
        //1.2得到客户端
        CuratorFramework client = getClient();
        //3.启动客户端
        client.start();
        //4.得到节点数据
        byte[] bytes = client.getData().forPath("/client");
        System.out.println(new String(bytes));
        //5.关闭客户端
        client.close();
    }

    //删除节点
    @Test
    public void delZNode() throws Exception {
        //1.2得到客户端
        CuratorFramework client = getClient();
        //3.启动客户端
        client.start();
        //4.删除节点
        client.delete().forPath("/client");
        //5.关闭客户端
        client.close();
    }

    //监听机制 watch
    @Test
    public void watch() throws Exception {
        //1.2得到客户端
        CuratorFramework client = getClient();
        //3.启动客户端
        client.start();
        //4.创建监听
        TreeCache treeCache = new TreeCache(client,"/client");
        treeCache.getListenable().addListener(new TreeCacheListener() {
            public void childEvent(CuratorFramework curatorFramework, TreeCacheEvent treeCacheEvent) throws Exception {
                ChildData data = treeCacheEvent.getData();
                if (data != null) {
                    switch (treeCacheEvent.getType()) {
                        case NODE_ADDED: //添加
                            System.out.println(data.getPath()+"被添加"+"数据---"+new String(data.getData()));
                            break;
                        case NODE_REMOVED: //移除
                            System.out.println(data.getPath()+"被移除");
                            break;
                        case NODE_UPDATED://更新
                            System.out.println(data.getPath()+"被修改"+"数据---"+new String(data.getData()));
                            break;
                    }
                }
            }
        });
        //5.启动监听
        treeCache.start();
        try {
            Thread.sleep(1000000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    //创建客户端
    private CuratorFramework getClient() {
        //1.创建策略
        RetryPolicy policy = new ExponentialBackoffRetry(1000,1);
        //主机列表 [集群用逗号隔开]
        String connectString = "192.168.110.110:2181,192.168.110.120:2181,192.168.110.130:2181";
        //2.创建客户端
        CuratorFramework client = CuratorFrameworkFactory.newClient(connectString, 8000, 8000, policy);
        return client;
    }