@Override
      public void bulkHFile(final byte[] family, final FileStatus hfile) {
        long length = hfile.getLen();
        if (
          length > conf.getLong(HConstants.HREGION_MAX_FILESIZE, HConstants.DEFAULT_MAX_FILE_SIZE)
        ) {
          LOG.warn("Trying to bulk load hfile " + hfile.getPath() + " with size: " + length
            + " bytes can be problematic as it may lead to oversplitting.");
        }
        ret.add(new LoadQueueItem(family, hfile.getPath()));
      }
Walk the given directory for all HFiles, and return a Queue containing all such files.
hbase-server/src/main/java/org/apache/hadoop/hbase/tool/BulkLoadHFilesTool.java