从Zookeeper获取HDFS的Active名称节点信息

String hadoopZkNode = "/hadoop-ha/${cluster_name}/ActiveStandbyElectorLock";
ZooKeeper  keeper = new ZooKeeper(${zookeeperConnection}, 10000, new SimpleWatcher());
Stat stat = new Stat();
byte[] data = keeper.getData(hadoopZkNode, new SimpleWatcher(), stat);

//由于HDFS在向Zookeeper上写数据之前对数据进行了序列化，所以在获取到字节数组时需要调用相应的反序列化方法进行反序列化
ActiveNodeInfo activeNodeInfo = HAZKInfoProtos.ActiveNodeInfo.parseFrom(data);