如何定义帮助选项和其他必需选项？

Question

I need to have help option (-h) and two other required options (-u, -p) coexist together..

private static Options buildOptions() {
    Options options = new Options();

    Option help = new Option("h", "help", false, "print this message");     

    Option user = OptionBuilder.hasArg()
                .isRequired(true)
                .withArgName("username")                   
                .withDescription("use given user name for login")
                .withLongOpt("user")
                .create("u");

    Option pass = OptionBuilder.hasArg()
            .isRequired(true)
            .withArgName("password")                   
            .withDescription("use given password for login")
            .withLongOpt("pass")
            .create("p");

    options.addOption(help);
    options.addOption(user);
    options.addOption(pass);
    return options;
}

But when I try to parse args without providing required parameters, I receive MissingOptionException. I am looking for a way to be able to pass in only a -h and be able to print out only the help.

Answer 1

I pre-parse the command line looking for help:

if ((args.length > 0) && (args[0].matches("^\\s*[-/]{0,2}[Hh](?i:elp)\\s*$"))) {
    usage();
}

I also look for -help anywhere in the command line so that I can use just tack it onto the end of a partial command line if I forget whether something is -debug or -dbg .