private void closeZk() {
    if (zookeeper != null) {
      try {
        zookeeper.close();
      } catch (InterruptedException e) {
        // Restore interrupt status
        Thread.currentThread().interrupt();
      }
      zookeeper = null;
    }
  }
A very simple read only zookeeper implementation without watcher support.
hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ReadOnlyZKClient.java