import org.apache.hadoop.hbase.ZNodeClearer; //导入依赖的package包/类
public int run(String args[]) throws Exception {
  Options opt = new Options();
  opt.addOption("minServers", true, "Minimum RegionServers needed to host user tables");
  opt.addOption("backup", false, "Do not try to become HMaster until the primary fails");


  CommandLine cmd;
  try {
    cmd = new GnuParser().parse(opt, args);
  } catch (ParseException e) {
    LOG.error("Could not parse: ", e);
    usage(null);
    return -1;
  }


  if (cmd.hasOption("minServers")) {
    String val = cmd.getOptionValue("minServers");
    getConf().setInt("hbase.regions.server.count.min",
                Integer.valueOf(val));
    LOG.debug("minServers set to " + val);
  }

  // check if we are the backup master - override the conf if so
  if (cmd.hasOption("backup")) {
    getConf().setBoolean(HConstants.MASTER_TYPE_BACKUP, true);
  }

  List<String> remainingArgs = cmd.getArgList();
  if (remainingArgs.size() != 1) {
    usage(null);
    return -1;
  }

  String command = remainingArgs.get(0);

  if ("start".equals(command)) {
    return startMaster();
  } else if ("stop".equals(command)) {
    return stopMaster();
  } else if ("clear".equals(command)) {
    return (ZNodeClearer.clear(getConf()) ? 0 : -1);
  } else {
    usage("Invalid command: " + command);
    return -1;
  }
}