public static void main(final String[] args) throws Exception {
    Option encodingOption =
      new Option("e", "blockEncoding", true, "Data block encoding; Default: FAST_DIFF");
    encodingOption.setRequired(false);
    options.addOption(encodingOption);

    Option ratioOption = new Option("r", "selectionRatio", true,
      "Ratio of selected rows using essential column family");
    ratioOption.setRequired(false);
    options.addOption(ratioOption);

    Option widthOption =
      new Option("w", "valueWidth", true, "Width of value for non-essential column family");
    widthOption.setRequired(false);
    options.addOption(widthOption);

    CommandLineParser parser = new GnuParser();
    CommandLine cmd = parser.parse(options, args);
    if (args.length < 1) {
      HelpFormatter formatter = new HelpFormatter();
      formatter.printHelp("TestJoinedScanners", options, true);
    }

    if (cmd.hasOption("e")) {
      blockEncoding = DataBlockEncoding.valueOf(cmd.getOptionValue("e"));
    }
    if (cmd.hasOption("r")) {
      selectionRatio = Integer.parseInt(cmd.getOptionValue("r"));
    }
    if (cmd.hasOption("w")) {
      valueWidth = Integer.parseInt(cmd.getOptionValue("w"));
    }
    // run the test
    TestJoinedScanners test = new TestJoinedScanners();
    test.testJoinedScanners();
  }
Command line interface:
@throws IOException if there is a bug while reading from disk
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestJoinedScanners.java