code: @Override
      public ZooNode getNodeRecrusively() {
          ZooNode root = new ZooNode(zooConf.getNodePathPrefix(), zooConf.getNodePathPrefix());
          root.setOpen(true);
          if (zkClient == null || zkClient.getState() != States.CONNECTED) {
              LOG.warn("Zookeeper not connected!");
              return root;
          }
          LOG.info("Start to get zoo tree recrusively...");
          long start = System.currentTimeMillis();
          setNodeRecrusively(root, 0);
          LOG.info("Getting zoo tree costs " + (System.currentTimeMillis() - start) + "ms");
          return root;
      }
docs: 递归地获取一颗节点树
  
  @return 节点树root节点
  @see com.baidu.beidou.navimgr.zoo.service.ZooService#getNodeRecrusively()