zookeeper-原生API实现（2）

Zookeeper

原生API的实现

• 连接Zookeeper

/**
 * @Author: zxx
 * @Date: 2020/3/30 20:43
 * @Description: 连接zookeeper
 */
public class ZKConnection {
    @Test
    public void zkconnect() throws IOException, InterruptedException {
        String ip="192.168.21.141:2181";
        // 计数器对象
        final CountDownLatch countDownLatch=new CountDownLatch(1);
        // 连接对象
        ZooKeeper zooKeeper=new ZooKeeper(ip, 5000, new Watcher() {
            public void process(WatchedEvent watchedEvent) {
                try {
                    //EventType = None时
                    if (watchedEvent.getType() == Watcher.Event.EventType.None) {
                        if (watchedEvent.getState() == Watcher.Event.KeeperState.SyncConnected) {
                            System.out.println("连接成功");
                            countDownLatch.countDown();
                        } else if (watchedEvent.getState() == Watcher.Event.KeeperState.Disconnected) {
                            System.out.println("断开连接");
                        } else if (watchedEvent.getState() == Watcher.Event.KeeperState.Expired) {
                            System.out.println("会话超时");
                        } else if (watchedEvent.getState() == Watcher.Event.KeeperState.AuthFailed) {
                            System.out.println("认证失败");
                        }
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
        countDownLatch.await();
        zooKeeper.close();
    }
}

• 创建节点

// 同步方式 
create(String path, byte[] data, List<ACL> acl, CreateMode createMode) 
// 异步方式 
create(String path, byte[] data, List<ACL> acl, CreateMode createMode， AsyncCallback.StringCallback callBack,Object ctx)

path - znode路径。例如，/node1 /node1/node11 
data - 要存储在指定znode路径中的数据 
acl - 要创建的节点的访问控制列表。zookeeper API提供了一个静态接口 
ZooDefs.Ids 来获取一些基本的acl列表。例如，ZooDefs.Ids.OPEN_ACL_UNSAFE 返回打开znode的acl列表。 createMode - 节点的类型,这是一个枚举。 
callBack-异步回调接口 
ctx-传递上下文参数

/**
 * @Author: zxx
 * @Date: 2020/3/30 20:49
 * @Description: 新增节点
 */
public class ZKCreate {

    private String IP = "192.168.21.141:2181";

    public static ZooKeeper zooKeeper;

    //连接zookeeper
    @Before
    public void before() throws InterruptedException, IOException {
        final CountDownLatch countDownLatch=new CountDownLatch(1);
        zooKeeper = new ZooKeeper(IP, 6000, new Watcher() {
            public void process(WatchedEvent watchedEvent) {
                if (watchedEvent.getState() == Event.KeeperState.SyncConnected){
                    countDownLatch.countDown();
                }
                System.out.println("path=" + watchedEvent.getPath());
                System.out.println("eventType=" + watchedEvent.getType());
            }
        });
        countDownLatch.await();
    }

    @After
    public void after() throws InterruptedException {
        zooKeeper.close();
    }

    @Test
    public void zkCreate1() throws KeeperException, InterruptedException {
        zooKeeper.create("/node1", "data".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE,CreateMode.PERSISTENT);
    }

    @Test
    public void zkCreate2() throws KeeperException, InterruptedException {
        zooKeeper.create("/node1", "data".getBytes(), ZooDefs.Ids.READ_ACL_UNSAFE,CreateMode.PERSISTENT);
    }

    @Test
    public void zkCreate3() throws KeeperException, InterruptedException {
        List<ACL> acls = new ArrayList<ACL>();
        //授权模式和对象
        Id id = new Id("world", "anyone");
        acls.add(new ACL(ZooDefs.Perms.READ, id));
        acls.add(new ACL(ZooDefs.Perms.CREATE, id));
        zooKeeper.create("/node1", "data".getBytes(), acls,CreateMode.PERSISTENT);
    }

    @Test
    public void zkCreate4() throws KeeperException, InterruptedException {
        //auth授权
        zooKeeper.addAuthInfo("digest", "username:123456".getBytes());
        zooKeeper.create("/node1", "data".getBytes(), ZooDefs.Ids.CREATOR_ALL_ACL,CreateMode.PERSISTENT);
    }

    @Test
    public void zkCreate5() throws Exception {
        // 持久化顺序节点
        // Ids.OPEN_ACL_UNSAFE world:anyone:cdrwa
        String result = zooKeeper.create("/create/node1", "node1".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE,
                CreateMode.PERSISTENT_SEQUENTIAL);
        System.out.println(result);
    }


}

• 更新节点

// 同步方式 
setData(String path, byte[] data, int version) 
// 异步方式 
setData(String path, byte[] data, int version，AsyncCallback.StatCallback callBack， Object ctx)

path- znode路径 
data - 要存储在指定znode路径中的数据。 
version- znode的当前版本。每当数据更改时，ZooKeeper会更新znode的版本号。
callBack-异步回调接口 ctx-传递上下文参数

/**
 * @Author: zxx
 * @Date: 2020/3/30 20:49
 * @Description: 更新节点
 */
public class ZKUpdate {

    private String IP = "192.168.21.141:2181";

    public static ZooKeeper zooKeeper;

    //连接zookeeper
    @Before
    public void before() throws InterruptedException, IOException {
        final CountDownLatch countDownLatch=new CountDownLatch(1);
        zooKeeper = new ZooKeeper(IP, 6000, new Watcher() {
            public void process(WatchedEvent watchedEvent) {
                if (watchedEvent.getState() == Event.KeeperState.SyncConnected){
                    countDownLatch.countDown();
                }
                System.out.println("path=" + watchedEvent.getPath());
                System.out.println("eventType=" + watchedEvent.getType());
            }
        });
        countDownLatch.await();
    }

    @After
    public void after() throws InterruptedException {
        zooKeeper.close();
    }

    @Test
    public void zkCreate1() throws KeeperException, InterruptedException {
        // arg1:节点的路径
        // arg2:节点的数据
        // arg3:版本号 -1代表版本号不作为修改条件
        Stat stat=zooKeeper.setData("/node1","nodedata".getBytes(),2);
        // 节点的版本号
        System.out.println(stat.getVersion());
        // 节点的创建时间
        System.out.println(stat.getCtime());
    }

    @Test
    public void zkCreate2() throws KeeperException, InterruptedException {
        // 异步方式修改节点
        zooKeeper.setData("/node2", "node2".getBytes(), -1, new AsyncCallback.StatCallback() {
        public void processResult(int rc, String path, Object ctx, Stat stat) {
            // 0 代表修改成功
             System.out.println(rc);
            // 修改节点的路径
             System.out.println(path);
             // 上线文的参数对象
            System.out.println(ctx);
            // 版本信息
            System.out.println(stat.getVersion());
        } },"I am Context");
        Thread.sleep(50000);
        System.out.println("结束");
    }

}

• 删除节点

// 同步方式 
delete(String path, int version) 
// 异步方式 
delete(String path, int version, AsyncCallback.VoidCallback callBack, Object ctx)

path - znode路径。 
version - znode的当前版本 
callBack-异步回调接口 
ctx-传递上下文参数

public class ZKDelete {
    String IP = "192.168.21.141:2181";
    ZooKeeper zooKeeper;

    @Before
    public void before() throws Exception {
        final CountDownLatch countDownLatch = new CountDownLatch(1);
        // arg1:zookeeper服务器的ip地址和端口号
        // arg2:连接的超时时间  以毫秒为单位
        // arg3:监听器对象
        zooKeeper = new ZooKeeper(IP, 5000, new Watcher() {
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.SyncConnected) {
                    System.out.println("连接创建成功!");
                    countDownLatch.countDown();
                }
            }
        });
        // 使主线程阻塞等待
        countDownLatch.await();
    }

    @After
    public void after() throws Exception {
        zooKeeper.close();
    }

    @Test
    public void delete1() throws Exception {
        // arg1:删除节点的节点路径
        // arg2:数据版本信息 -1代表删除节点时不考虑版本信息
        zooKeeper.delete("/delete/node1",-1);
    }

    @Test
    public void delete2() throws Exception {
        // 异步使用方式
        zooKeeper.delete("/delete/node2", -1, new AsyncCallback.VoidCallback() {
            public void processResult(int rc, String path, Object ctx) {
                // 0代表删除成功
                System.out.println(rc);
                // 节点的路径
                System.out.println(path);
                // 上下文参数对象
                System.out.println(ctx);
            }
        },"I am Context");
        Thread.sleep(10000);
        System.out.println("结束");
    }
}

• 查看节点

// 同步方式 
getData(String path, boolean b, Stat stat) 
// 异步方式 
getData(String path, boolean b，AsyncCallback.DataCallback callBack， Object ctx)

path - znode路径。 
b- 是否使用连接对象中注册的监视器。 
stat - 返回znode的元数据。 
callBack-异步回调接口 
ctx-传递上下文参数

public class ZKGet {

    String IP = "192.168.21.141:2181";
    ZooKeeper zooKeeper;

    @Before
    public void before() throws Exception {
        final CountDownLatch countDownLatch = new CountDownLatch(1);
        // arg1:zookeeper服务器的ip地址和端口号
        // arg2:连接的超时时间  以毫秒为单位
        // arg3:监听器对象
        zooKeeper = new ZooKeeper(IP, 5000, new Watcher() {
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.SyncConnected) {
                    System.out.println("连接创建成功!");
                    countDownLatch.countDown();
                }
            }
        });
        // 使主线程阻塞等待
        countDownLatch.await();
    }

    @After
    public void after() throws Exception {
        zooKeeper.close();
    }

    @Test
    public void get1() throws Exception {
        // arg1:节点的路径
        // arg3:读取节点属性的对象
        Stat stat=new Stat();
        byte [] bys=zooKeeper.getData("/get/node1",false,stat);
        // 打印数据
        System.out.println(new String(bys));
        // 版本信息
        System.out.println(stat.getVersion());
    }

    @Test
    public void get2() throws Exception {
        //异步方式
        zooKeeper.getData("/get/node1", false, new AsyncCallback.DataCallback() {
            public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
                // 0代表读取成功
                System.out.println(rc);
                // 节点的路径
                System.out.println(path);
                // 上下文参数对象
                System.out.println(ctx);
                // 数据
                System.out.println(new String(data));
                // 属性对象
                System.out.println(stat.getVersion());
            }
        },"I am Context");
        Thread.sleep(10000);
        System.out.println("结束");
    }
}

• 查看子节点

// 同步方式 
getChildren(String path, boolean b) 
// 异步方式 
getChildren(String path, boolean b,AsyncCallback.ChildrenCallback callBack,Object ctx)

path - Znode路径。
b- 是否使用连接对象中注册的监视器。 
callBack - 异步回调接口。 
ctx-传递上下文参数

public class ZKGetChid {
    String IP = "192.168.21.141:2181";
    ZooKeeper zooKeeper;

    @Before
    public void before() throws Exception {
        final CountDownLatch countDownLatch = new CountDownLatch(1);
        // arg1:zookeeper服务器的ip地址和端口号
        // arg2:连接的超时时间  以毫秒为单位
        // arg3:监听器对象
        zooKeeper = new ZooKeeper(IP, 5000, new Watcher() {
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.SyncConnected) {
                    System.out.println("连接创建成功!");
                    countDownLatch.countDown();
                }
            }
        });
        // 使主线程阻塞等待
        countDownLatch.await();
    }

    @After
    public void after() throws Exception {
        zooKeeper.close();
    }

    @Test
    public void get1() throws Exception {
        // arg1:节点的路径
        List<String> list = zooKeeper.getChildren("/get", false);
        for (String str : list) {
            System.out.println(str);
        }
    }

    @Test
    public void get2() throws Exception {
        // 异步用法
        zooKeeper.getChildren("/get", false, new AsyncCallback.ChildrenCallback() {
            public void processResult(int rc, String path, Object ctx, List<String> children) {
                // 0代表读取成功
                System.out.println(rc);
                // 节点的路径
                System.out.println(path);
                // 上下文参数对象
                System.out.println(ctx);
                // 子节点信息
                for (String str : children) {
                    System.out.println(str);
                }
            }
        },"I am Context");
        Thread.sleep(10000);
        System.out.println("结束");
    }
}