如何使Java CLI解析库Jopt Simple解析参数而没有任何选择？

Question

So I'm building a Java CLI application that will have features similair to Windows's dir. I'm using the jopt-simple 4.9 library for my CLI parsing needs, and for acquiring options it seems pretty straightforward...

public static void main(String[] args) throws Exception {
    OptionParser parser = new OptionParser("a::b?*");

    OptionSet options = parser.parse(args);

    parser.accepts("a", "Display all");
    parser.accepts("b", "Bare output without metadata");
    parser.accepts("?", "Displays this help prompt");

But what if I want to run my app without any args? Like I would run dir or ls to display local contents. And what if I want to run my app without any options? Like if I'm just telling dir or ls which directory I want it to print out.

Answer 1

OK, so to achieve this is simply used the fact the JOpt also parses non-option arguments:

OptionParser parser = new OptionParser("a::b?*");
    parser.allowsUnrecognizedOptions();

//  In case the user specifies a path instead of just running the command 
//  locally, create an array out of the parsed directory strings.
String[] dirStringArray = options.nonOptionArguments().toArray(new String[options.nonOptionArguments().size()]);