public String checksumRows(final Table table) throws Exception {
    MessageDigest digest = MessageDigest.getInstance("MD5");
    try (ResultScanner results = table.getScanner(new Scan())) {
      for (Result res : results) {
        digest.update(res.getRow());
      }
    }
    return digest.toString();
  }
Return an md5 digest of the entire contents of a table.
hbase-server/src/test/java/org/apache/hadoop/hbase/HBaseTestingUtil.java