zookeeper生成序列号2种方式，zookeeper序列号2种,依赖zookeeper服

zookeeper生成序列号2种方式，zookeeper序列号2种,依赖zookeeper服

依赖zookeeper服务生成分布式一致的序列号两种方式``````javapackage zk.seq;import com.github.zkclient.IZkChildListener;import com.github.zkclient.ZkClient;import org.apache.zookeeper.data.Stat;import java.util.Arrays;import java.util.List;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.TimeUnit;/** * Author : secondriver */public class GenerateSeq {    //提前创建好存储Seq的"/createSeq"结点 CreateMode.PERSISTENT    public static final String SEQ_ZNODE = "/seq";    //提前创建好锁对象的结点"/lock" CreateMode.PERSISTENT    public static final String LOCK_ZNODE = "/lock";    public static void main(String[] args) {        final ExecutorService service = Executors.newFixedThreadPool(20);        for (int i = 0; i < 20; i++) {            service.execute(new Task2("[Concurrent-" + i + "]"));        }        if (!service.isShutdown()) {            try {                service.shutdown();                if (!service.awaitTermination(10, TimeUnit.SECONDS)) {                    service.shutdownNow();                }            } catch (InterruptedException e) {                service.shutdownNow();                System.out.println(e.getMessage());            }        }    }    public static class Task1 implements Runnable {        private final String taskName;        public Task1(String taskName) {            this.taskName = taskName;        }        @Override        public void run() {            ZkClient zkClient = new ZkClient("192.168.88.153:2181", 3000, 1000);            Stat stat = zkClient.writeData(SEQ_ZNODE, new byte[0], -1);            int versionAsSeq = stat.getVersion();            //versionAsSeq 最终的序列号            System.out.println(taskName + " obtain seq=" + versionAsSeq);            zkClient.close();        }    }    //分布式锁实现    public static class Task2 implements Runnable, IZkChildListener {        private final String taskName;        private final ZkClient zkClient;        private final String lockPrefix = "/loc";        private final String selfZnode;        public Task2(String taskName) {            this.taskName = taskName;            zkClient = new ZkClient("192.168.88.153:2181", 30000, 10000);            selfZnode = zkClient.createEphemeralSequential(LOCK_ZNODE + lockPrefix, new byte[0]);        }        @Override        public void run() {            zkClient.subscribeChildChanges(LOCK_ZNODE, this);            do {            } while (zkClient.isConnected());        }        private void createSeq() {            Stat stat = new Stat();            byte[] oldData = zkClient.readData(LOCK_ZNODE, stat);            byte[] newData = update(oldData);            zkClient.writeData(LOCK_ZNODE, newData);            //new String(newData) 最终的序列号            System.out.println(taskName + selfZnode + " obtain seq=" + new String(newData));        }        private byte[] update(byte[] currentData) {            String s = new String(currentData);            int d = Integer.parseInt(s);            d = d + 1;            s = String.valueOf(d);            return s.getBytes();        }        @Override        public void handleChildChange(String parentPath, List<String> currentChildren) throws Exception {            String[] childrensZnode = currentChildren.toArray(new String[currentChildren.size()]);            Arrays.sort(childrensZnode);            String minZnode = LOCK_ZNODE + "/" + childrensZnode[0];            if (selfZnode.equals(minZnode)) {                createSeq();                zkClient.unsubscribeChildChanges(LOCK_ZNODE, this);                zkClient.delete(selfZnode);                zkClient.close();            }        }    }}