public enum CreateMode {
   
    /**
     * 持久节点：节点创建后，会一直存在，不会因客户端会话失效而删除；
     */
    PERSISTENT (0, false, false),

    /**
     * 持久顺序节点：基本特性与持久节点一致，创建节点的过程中，zookeeper会在其名字后自动追加一个单调增长的数字后缀，作为新的节点名； 
     */
    PERSISTENT_SEQUENTIAL (2, false, true),

    /**
     * 临时节点：客户端会话失效或连接关闭后，该节点会被自动删除，且不能再临时节点下面创建子节点，否则报如下错（org.apache.zookeeper.KeeperException$NoChildrenForEphemeralsException: KeeperErrorCode = NoChildrenForEphemerals for /node/child）；
     */
    EPHEMERAL (1, true, false),

    /**
     * 临时顺序节点：基本特性与临时节点一致，创建节点的过程中，zookeeper会在其名字后自动追加一个单调增长的数字后缀，作为新的节点名； 
     */
    EPHEMERAL_SEQUENTIAL (3, true, true);
    private static final Logger LOG = LoggerFactory.getLogger(CreateMode.class);
    private boolean ephemeral;
    private boolean sequential;
    private int flag;
    CreateMode(int flag, boolean ephemeral, boolean sequential) {
        this.flag = flag;
        this.ephemeral = ephemeral;
        this.sequential = sequential;
    }
    public boolean isEphemeral() {
        return ephemeral;
    }
    public boolean isSequential() {
        return sequential;
    }
    public int toFlag() {
        return flag;
    }
    static public CreateMode fromFlag(int flag) throws KeeperException {
        switch(flag) {
        case 0: return CreateMode.PERSISTENT;
        case 1: return CreateMode.EPHEMERAL;
        case 2: return CreateMode.PERSISTENT_SEQUENTIAL;
        case 3: return CreateMode.EPHEMERAL_SEQUENTIAL ;
        default:
            LOG.error("Received an invalid flag value to convert to a CreateMode");
            throw new KeeperException.BadArgumentsException();
        }
    }
}