10 분 시리즈-zookeeper 입문

# server.A=host1:B:C
# A: myid  
# B：      
# C：       
server.2=host1:2888:3888
server.3=host2:2888:3888
server.4=host3:2888:3888

package org.apache.zookeeper.server.quorum;

public interface Election {

    Vote lookForLeader() throws InterruptedException;
    void shutdown();

}

    <dependencies>
        <dependency>
            <groupId>junitgroupId>
            <artifactId>junitartifactId>
            <version>4.12version>
        dependency>

        <dependency>
            <groupId>log4jgroupId>
            <artifactId>log4jartifactId>
            <version>1.2.17version>
        dependency>

        <dependency>
            <groupId>org.apache.zookeepergroupId>
            <artifactId>zookeeperartifactId>
            <version>3.4.10version>
        dependency>
    dependencies>

    /**
     *        
     */
    private static String connectString = "localhost:2181";
    /**
     *     
     */
    private static int sessionTimeout = 2000;
    /**
     * client
     */
    private static ZooKeeper zk;

    @BeforeClass
    public static void init() throws IOException {
        zk = new ZooKeeper(connectString, sessionTimeout, watchedEvent -> {

        });
    }
	
    @AfterClass
    public static void afterClass() throws Exception {
        zk.close();
    }	

    @Test
    public void createNode() throws KeeperException, InterruptedException {
        String path = zk.create("/super", "jimo".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        assertEquals("/super", path);
    }

    @Test
    public void getNode() throws KeeperException, InterruptedException {
        List<String> children = zk.getChildren("/", false);
        children.forEach(System.out::println);
    }

    @Test
    public void getNodeWatch() throws KeeperException, InterruptedException {
        zk.getChildren("/", watcher -> {
            try {
                getNode();
            } catch (Exception e) {
                e.printStackTrace();
            }
        });

        TimeUnit.MINUTES.sleep(1L);
    }

    @Test
    public void nodeExist() throws KeeperException, InterruptedException {
        Stat exists = zk.exists("/super", false);
        assertNotNull(exists);
        Stat existNon = zk.exists("/hehe", false);
        assertNull(existNon);
    }