private DataInput getNextStream() {
    try {
      if (resDir != null && resDirFilesNum < resDirPaths.length
          && (resDirPaths[resDirFilesNum] != null)) {
        return resFs.open(resDirPaths[resDirFilesNum++]);
      }
    } catch (IOException e) {
      LOG.info("getNextStream error", e);
    }
    return null;
  }
@param resDir
         the resDir to set
ql/src/java/org/apache/hadoop/hive/ql/Context.java