zookeeper选主测试

<!-- zookeeper 客户端 -->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>2.13.0</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>2.13.0</version>
</dependency>

package com.cookie;

/**
 * @author cxq
 * @version 1.0
 * @date 2020/7/10 17:35
 * @desc
 */

        import org.apache.curator.framework.CuratorFramework;
        import org.apache.curator.framework.CuratorFrameworkFactory;
        import org.apache.curator.framework.recipes.leader.LeaderSelector;
        import org.apache.curator.framework.recipes.leader.LeaderSelectorListenerAdapter;
        import org.apache.curator.retry.ExponentialBackoffRetry;

        import java.util.HashMap;
        import java.util.Map;
        import java.util.concurrent.TimeUnit;

public class SelectMasterTest {

    private String selectMasterZookeeper="192.168.200.129:2181";

    //可以放很多节点
    Map<String, Boolean> masterMap = new HashMap<String, Boolean>();


    /**
     * 选主
     * @param leaderPath  zookeeper目录节点
     */
    public void selectMaster (String leaderPath) {
        CuratorFramework client = CuratorFrameworkFactory.builder().
                connectString(selectMasterZookeeper)
                .sessionTimeoutMs(5000)  //超时时间
                .retryPolicy(new ExponentialBackoffRetry(1000, 3)) //连接不上重试三次
                .build();
        client.start();

        //争抢注册节点
        @SuppressWarnings("resource")
        LeaderSelector selector = new LeaderSelector(client, leaderPath,
                new LeaderSelectorListenerAdapter() {

                    @Override
                    public void takeLeadership(CuratorFramework client) throws Exception {
                        //如果争抢到当前注册节点
                        masterMap.put(leaderPath, true);
                        while (true) {
                            //抢占当前节点
                            TimeUnit.SECONDS.sleep(3);
                        }
                    }
                });
        masterMap.put(leaderPath, false);
        selector.autoRequeue();
        selector.start();
    }

    public boolean checkMaster (String leaderPath) {
        Boolean isMaster = masterMap.get(leaderPath);
        return isMaster == null ? false : isMaster;
    }

    public static void main(String[] args) throws InterruptedException {
        String leaderPath = "/master";
        SelectMasterTest selectMaster = new SelectMasterTest();
        selectMaster.selectMaster(leaderPath);

        TimeUnit.SECONDS.sleep(1);

        while(true) {
            if(selectMaster.checkMaster(leaderPath)){
                System.out.println(" 节点1 主节点 ");
            }else {
                System.out.println(" 节点1 从节点 ");
            }
            TimeUnit.SECONDS.sleep(6);
        }
    }
}