zookeeper-原生API實現（2）

Zookeeper

原生API的實現

• 連接Zookeeper

/**
 * @Author: zxx
 * @Date: 2020/3/30 20:43
 * @Description: 連接zookeeper
 */
public class ZKConnection {
    @Test
    public void zkconnect() throws IOException, InterruptedException {
        String ip="192.168.21.141:2181";
        // 計數器對象
        final CountDownLatch countDownLatch=new CountDownLatch(1);
        // 連接對象
        ZooKeeper zooKeeper=new ZooKeeper(ip, 5000, new Watcher() {
            public void process(WatchedEvent watchedEvent) {
                try {
                    //EventType = None時
                    if (watchedEvent.getType() == Watcher.Event.EventType.None) {
                        if (watchedEvent.getState() == Watcher.Event.KeeperState.SyncConnected) {
                            System.out.println("連接成功");
                            countDownLatch.countDown();
                        } else if (watchedEvent.getState() == Watcher.Event.KeeperState.Disconnected) {
                            System.out.println("斷開連接");
                        } else if (watchedEvent.getState() == Watcher.Event.KeeperState.Expired) {
                            System.out.println("會話超時");
                        } else if (watchedEvent.getState() == Watcher.Event.KeeperState.AuthFailed) {
                            System.out.println("認證失敗");
                        }
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
        countDownLatch.await();
        zooKeeper.close();
    }
}

• 創建節點

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

path - znode路徑。例如，/node1 /node1/node11 
data - 要存儲在指定znode路徑中的數據 
acl - 要創建的節點的訪問控制列表。zookeeper API提供了一個靜態接口 
ZooDefs.Ids 來獲取一些基本的acl列表。例如，ZooDefs.Ids.OPEN_ACL_UNSAFE 返回打開znode的acl列表。 createMode - 節點的類型,這是一個枚舉。 
callBack-異步回調接口 
ctx-傳遞上下文參數

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

    private String IP = "192.168.21.141:2181";

    public static ZooKeeper zooKeeper;

    //連接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>();
        //授權模式和對象
        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授權
        zooKeeper.addAuthInfo("digest", "username:123456".getBytes());
        zooKeeper.create("/node1", "data".getBytes(), ZooDefs.Ids.CREATOR_ALL_ACL,CreateMode.PERSISTENT);
    }

    @Test
    public void zkCreate5() throws Exception {
        // 持久化順序節點
        // 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);
    }


}

• 更新節點

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

path- znode路徑 
data - 要存儲在指定znode路徑中的數據。 
version- znode的當前版本。每當數據更改時，ZooKeeper會更新znode的版本號。
callBack-異步回調接口 ctx-傳遞上下文參數

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

    private String IP = "192.168.21.141:2181";

    public static ZooKeeper zooKeeper;

    //連接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:節點的路徑
        // arg2:節點的數據
        // arg3:版本號 -1代表版本號不作爲修改條件
        Stat stat=zooKeeper.setData("/node1","nodedata".getBytes(),2);
        // 節點的版本號
        System.out.println(stat.getVersion());
        // 節點的創建時間
        System.out.println(stat.getCtime());
    }

    @Test
    public void zkCreate2() throws KeeperException, InterruptedException {
        // 異步方式修改節點
        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);
            // 修改節點的路徑
             System.out.println(path);
             // 上線文的參數對象
            System.out.println(ctx);
            // 版本信息
            System.out.println(stat.getVersion());
        } },"I am Context");
        Thread.sleep(50000);
        System.out.println("結束");
    }

}

• 刪除節點

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

path - znode路徑。 
version - znode的當前版本 
callBack-異步回調接口 
ctx-傳遞上下文參數

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服務器的ip地址和端口號
        // arg2:連接的超時時間  以毫秒爲單位
        // arg3:監聽器對象
        zooKeeper = new ZooKeeper(IP, 5000, new Watcher() {
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.SyncConnected) {
                    System.out.println("連接創建成功!");
                    countDownLatch.countDown();
                }
            }
        });
        // 使主線程阻塞等待
        countDownLatch.await();
    }

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

    @Test
    public void delete1() throws Exception {
        // arg1:刪除節點的節點路徑
        // arg2:數據版本信息 -1代表刪除節點時不考慮版本信息
        zooKeeper.delete("/delete/node1",-1);
    }

    @Test
    public void delete2() throws Exception {
        // 異步使用方式
        zooKeeper.delete("/delete/node2", -1, new AsyncCallback.VoidCallback() {
            public void processResult(int rc, String path, Object ctx) {
                // 0代表刪除成功
                System.out.println(rc);
                // 節點的路徑
                System.out.println(path);
                // 上下文參數對象
                System.out.println(ctx);
            }
        },"I am Context");
        Thread.sleep(10000);
        System.out.println("結束");
    }
}

• 查看節點

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

path - znode路徑。 
b- 是否使用連接對象中註冊的監視器。 
stat - 返回znode的元數據。 
callBack-異步回調接口 
ctx-傳遞上下文參數

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服務器的ip地址和端口號
        // arg2:連接的超時時間  以毫秒爲單位
        // arg3:監聽器對象
        zooKeeper = new ZooKeeper(IP, 5000, new Watcher() {
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.SyncConnected) {
                    System.out.println("連接創建成功!");
                    countDownLatch.countDown();
                }
            }
        });
        // 使主線程阻塞等待
        countDownLatch.await();
    }

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

    @Test
    public void get1() throws Exception {
        // arg1:節點的路徑
        // arg3:讀取節點屬性的對象
        Stat stat=new Stat();
        byte [] bys=zooKeeper.getData("/get/node1",false,stat);
        // 打印數據
        System.out.println(new String(bys));
        // 版本信息
        System.out.println(stat.getVersion());
    }

    @Test
    public void get2() throws Exception {
        //異步方式
        zooKeeper.getData("/get/node1", false, new AsyncCallback.DataCallback() {
            public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
                // 0代表讀取成功
                System.out.println(rc);
                // 節點的路徑
                System.out.println(path);
                // 上下文參數對象
                System.out.println(ctx);
                // 數據
                System.out.println(new String(data));
                // 屬性對象
                System.out.println(stat.getVersion());
            }
        },"I am Context");
        Thread.sleep(10000);
        System.out.println("結束");
    }
}

• 查看子節點

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

path - Znode路徑。
b- 是否使用連接對象中註冊的監視器。 
callBack - 異步回調接口。 
ctx-傳遞上下文參數

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服務器的ip地址和端口號
        // arg2:連接的超時時間  以毫秒爲單位
        // arg3:監聽器對象
        zooKeeper = new ZooKeeper(IP, 5000, new Watcher() {
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.SyncConnected) {
                    System.out.println("連接創建成功!");
                    countDownLatch.countDown();
                }
            }
        });
        // 使主線程阻塞等待
        countDownLatch.await();
    }

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

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

    @Test
    public void get2() throws Exception {
        // 異步用法
        zooKeeper.getChildren("/get", false, new AsyncCallback.ChildrenCallback() {
            public void processResult(int rc, String path, Object ctx, List<String> children) {
                // 0代表讀取成功
                System.out.println(rc);
                // 節點的路徑
                System.out.println(path);
                // 上下文參數對象
                System.out.println(ctx);
                // 子節點信息
                for (String str : children) {
                    System.out.println(str);
                }
            }
        },"I am Context");
        Thread.sleep(10000);
        System.out.println("結束");
    }
}