java command line options

CommonsCLI.java

import org.apache.commons.cli.*;

/** TODO: which maven artifact version do we need? */
public class CommandLineOptionsExample {

  public static void main(String[] args) {
    String port;
    _parseOptions: {

      Options options = new Options()
	.addOption("h", "help", false, "show help.");

      Option option = Option.builder("a").longOpt("block-size").desc("use SIZE-byte blocks").hasArg().argName("SIZE")
          .build();
      options.addOption(option);

      // This doesn't work with java 7
      // "hasarg" is needed when the option takes a value
      options.addOption(Option.builder("p").longOpt("port").hasArg().required().build());

      try {
        CommandLine cmd = new DefaultParser().parse(options, args);
        port = cmd.getOptionValue("p", "4444");
        System.out.println("CommandLineOptionsExample.parse() - SRIDHAR: port = " + port);
        System.out.println("CommandLineOptionsExample.parse() - SRIDHAR: a = " + cmd.getOptionValue("a"));

        if (cmd.hasOption("h")) {
          // This prints out some help
          HelpFormatter formater = new HelpFormatter();

          formater.printHelp("Main", options);
          System.exit(0);
        }
      } catch (ParseException e) {
        e.printStackTrace();
      }
    }
  }
}