public static byte[] getData(ZKWatcher zkw, String znode)
    throws KeeperException, InterruptedException {
    try {
      byte[] data = zkw.getRecoverableZooKeeper().getData(znode, null, null);
      logRetrievedMsg(zkw, znode, data, false);
      return data;
    } catch (KeeperException.NoNodeException e) {
      LOG.debug(zkw.prefix("Unable to get data of znode " + znode + " "
        + "because node does not exist (not an error)"));
      return null;
    } catch (KeeperException e) {
      LOG.warn(zkw.prefix("Unable to get data of znode " + znode), e);
      zkw.keeperException(e);
      return null;
    }
  }
Get znode data. Does not set a watcher.
@return ZNode data, null if the node does not exist or if there is an error.
hbase-zookeeper/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java