原文链接：https://www.dubby.cn/detail.html?id=9099

提供了一个笼统级别更高的API，来操作Zookeeper，相似Guava提供的很多工具，让Java书写起来更加方便。至于有没有用，那就要看每个人自己的了解了。

1、依赖

<dependency>    <groupId>org.apache.curator</groupId>    <artifactId>curator-framework</artifactId>    <version>2.8.0</version></dependency>

更多版本和依赖

2、连接Zookeeper

RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);CuratorFramework client = CuratorFrameworkFactory.newClient("127.0.0.1:2181", retryPolicy);client.start();

3、增删改查

/** * Zookeeper的CRUD操作 */public class CrudExamples {    /**     * 给指定的ZNode设置值，不能嵌套创立目录     * 假如节点已经存在，会抛异常org.apache.zookeeper.KeeperException$NodeExistsException: KeeperErrorCode = NodeExists for /path     */    public static void create(CuratorFramework client, String path, byte[] payload) throws Exception {        client.create().forPath(path, payload);    }    /**     * 创立临时节点     * 需要注意：虽说临时节点是session失效后立刻删除，但是并不是client一断开连接，session就立刻会失效     * 失效是由zk服务端控制的，每次连接时，用户端和服务端会协商一个正当的超时时间     * 假如超过了超时时间client都一直美哦与发送心跳，才回真的删除这个session创立的临时节点     */    public static void createEphemeral(CuratorFramework client, String path, byte[] payload) throws Exception {        client.create().withMode(CreateMode.EPHEMERAL).forPath(path, payload);    }    public static String createEphemeralSequential(CuratorFramework client, String path, byte[] payload) throws Exception {        return client.create().withProtection().withMode(CreateMode.EPHEMERAL_SEQUENTIAL).forPath(path, payload);    }    public static void setData(CuratorFramework client, String path, byte[] payload) throws Exception {        client.setData().forPath(path, payload);    }    public static void setDataAsync(CuratorFramework client, String path, byte[] payload) throws Exception {        CuratorListener listener = new CuratorListener() {            @Override            public void eventReceived(CuratorFramework client, CuratorEvent event) throws Exception {                if (event != null)                    System.out.println(event.toString());            }        };        client.getCuratorListenable().addListener(listener);        client.setData().inBackground().forPath(path, payload);    }    public static void setDataAsyncWithCallback(CuratorFramework client, BackgroundCallback callback, String path, byte[] payload) throws Exception {        client.setData().inBackground(callback).forPath(path, payload);    }    public static void delete(CuratorFramework client, String path) throws Exception {        client.delete().forPath(path);    }    public static void guaranteedDelete(CuratorFramework client, String path) throws Exception {        client.delete().guaranteed().forPath(path);    }    public static List<String> watchedGetChildren(CuratorFramework client, String path) throws Exception {        return client.getChildren().watched().forPath(path);    }    public static List<String> watchedGetChildren(CuratorFramework client, String path, Watcher watcher) throws Exception {        return client.getChildren().usingWatcher(watcher).forPath(path);    }}

使用上面的增删改查来测试：

public class CuratorStartupDemo {    private static CuratorFramework CLIENT;    private static final String CHARSET = "UTF-8";    static {        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);        CLIENT = CuratorFrameworkFactory.newClient("127.0.0.1:2181", retryPolicy);    }    public static void main(String[] args) throws Exception {        CLIENT.start();        System.out.println(CLIENT.getZookeeperClient().getConnectionTimeoutMs());        CrudExamples.create(CLIENT, "/x", "test".getBytes(CHARSET));        CrudExamples.createEphemeral(CLIENT, "/e", "test".getBytes(CHARSET));        CrudExamples.setData(CLIENT, "/x", UUID.randomUUID().toString().getBytes(CHARSET));        CrudExamples.setDataAsync(CLIENT, "/x", UUID.randomUUID().toString().getBytes(CHARSET));        CrudExamples.setDataAsyncWithCallback(CLIENT, ((client, event) -> {            System.out.println(event.getPath());        }), "/x", UUID.randomUUID().toString().getBytes(CHARSET));        CrudExamples.createEphemeralSequential(CLIENT, "/x", "test".getBytes(CHARSET));        CrudExamples.createEphemeralSequential(CLIENT, "/x", "test".getBytes(CHARSET));        CrudExamples.createEphemeralSequential(CLIENT, "/x", "test".getBytes(CHARSET));        CrudExamples.createEphemeralSequential(CLIENT, "/x", "test".getBytes(CHARSET));        CuratorListener listener = new CuratorListener() {            @Override            public void eventReceived(CuratorFramework client, CuratorEvent event) throws Exception {                if (event != null)                    System.out.println(event.toString());                //watcher是一次性的，每次watch后需要重新设置watcher                if ("/x".equals(event.getPath())) {                    CrudExamples.watchedGetChildren(CLIENT, "/x");                }            }        };        CLIENT.getCuratorListenable().addListener(listener);        CrudExamples.watchedGetChildren(CLIENT, "/x");        CrudExamples.create(CLIENT, "/x/a", null);        CrudExamples.create(CLIENT, "/x/b", null);        CrudExamples.delete(CLIENT, "/x/a");        CrudExamples.delete(CLIENT, "/x/b");        MyWatcher myWatcher = new MyWatcher("/x", CLIENT);        CrudExamples.watchedGetChildren(myWatcher.curatorFramework, myWatcher.getPath(), myWatcher);        System.out.println("task completed");        new CountDownLatch(1).await();    }    static class MyWatcher implements Watcher {        private String path;        private CuratorFramework curatorFramework;        public MyWatcher(String path, CuratorFramework curatorFramework) {            this.path = path;            this.curatorFramework = curatorFramework;        }        @Override        public void process(WatchedEvent event) {            System.out.println(event.toString());            try {                //watcher是一次性的，每次watch后需要重新设置watcher                CrudExamples.watchedGetChildren(this.curatorFramework, this.getPath(), this);            } catch (Exception e) {                e.printStackTrace();            }        }        public String getPath() {            return path;        }        public CuratorFramework getCuratorFramework() {            return curatorFramework;        }    }}