Zookeeper使用

刺骨的言语ヽ痛彻心扉 2022-02-16 04:37 133阅读 0赞

1、创建服务端ZookeeperServer

/**
     * 监听服务器动态上下线案例：服务端
     */
    public class ZookeeperServer {
        private String connectString="192.168.106.131:2181,192.168.106.132:2181,192.168.106.133:2181";
        private int sessionTimeout=2000;
        private ZooKeeper zkClient;
    
        public static void main(String[] args) throws IOException, KeeperException, InterruptedException {
            BasicConfigurator.configure();
            ZookeeperServer server = new ZookeeperServer();
            //1、连接Zookeeper集群
            server.getConnect();
            //2、注册节点
            server.regist(args[0]);
            //3、业务逻辑
            server.business();
        }
    
        private void getConnect() throws IOException {
            zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
                public void process(WatchedEvent watchedEvent) {
    
                }
            });
        }
    
        private void regist(String hostname) throws KeeperException, InterruptedException {
            zkClient.create("/servers/server", hostname.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
            System.out.println(hostname+" is online");
        }
    
        private void business() throws InterruptedException {
            Thread.sleep(Long.MAX_VALUE);
        }
    
    }

2、创建客户端ZookeeperClient

/**
     * 监听服务器动态上下线案例：客户端
     */
    public class ZookeeperClient {
        private String connectString="192.168.106.131:2181,192.168.106.132:2181,192.168.106.133:2181";
        private int sessionTimeout=2000;
        private ZooKeeper zkClient;
    
        public static void main(String[] args) throws IOException, KeeperException, InterruptedException {
            BasicConfigurator.configure();
            ZookeeperClient client = new ZookeeperClient();
            //1、获取Zookeeper连接
            client.getConnect();
            //2、注册监听
            client.getChildren();
            //3、业务逻辑
            client.business();
        }
    
        private void getConnect() throws IOException {
            zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
                public void process(WatchedEvent watchedEvent) {
                    try {
                        getChildren();
                    } catch (KeeperException e) {
                        e.printStackTrace();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    
        private void getChildren() throws KeeperException, InterruptedException {
            List<String> children = zkClient.getChildren("/servers", true);
    
            //存储服务器节点主机名称集合
            ArrayList<String> hosts = new ArrayList<String>();
            for(String child : children){
                byte[] data = zkClient.getData("/servers/" + child, false, null);
                hosts.add(new String(data));
            }
    
            //打印所有在线主机名称
            System.out.println(hosts);
        }
    
        private void business() throws InterruptedException {
            Thread.sleep(Long.MAX_VALUE);
        }
    
    }

3、测试Zookeeper

public class TestZookeeper {
    
        private String connectString="192.168.106.131:2181,192.168.106.132:2181,192.168.106.133:2181";
        private int sessionTimeout=2000;
        private ZooKeeper zkClient;
    
        /**获取Zookeeper客户端对象*/
        @Before
        public void init() throws IOException {
            BasicConfigurator.configure();
            zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
                public void process(WatchedEvent watchedEvent) {
                    List<String> children;
                    try {
                        children = zkClient.getChildren("/", true);
                        for(String child : children){
                            System.out.println(child);
                        }
                    } catch (KeeperException e) {
                        e.printStackTrace();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    
        /**创建Zookeeper节点*/
        @Test
        public void createNode() throws KeeperException, InterruptedException {
            String path = zkClient.create("/shanxi", "guxiang".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            System.out.println(path);
        }
    
        /**获取子节点并监控节点的变化*/
        @Test
        public void getDataAndWatch() throws KeeperException, InterruptedException {
            List<String> children = zkClient.getChildren("/", true);
            for(String child : children){
                System.out.println(child);
            }
            Thread.sleep(Long.MAX_VALUE);
        }
    
        /**判断Zookeeper节点是否存在*/
        @Test
        public void exist() throws KeeperException, InterruptedException {
            Stat exists = zkClient.exists("/shanxi", false);
            System.out.println(exists==null?"节点不存在":"节点存在");
        }
    
    }