Small example on how to use apache commons.

cli.java

import org.apache.commons.cli.*;

import java.io.PrintWriter;

public class CLI {

    private static final Option ARG_ADD = new Option("a", "addition", false, "Add two numbers together");
    private static final Option ARG_SUB = new Option("s", "subtraction", false, "Subtract two numbers");
    private static final Option ARG_MUL = new Option("m", "multiplication", false, "Multiply two numbers");
    private static final Option ARG_DIV = new Option("d", "division", false, "Divided two numbers");
    private static final Option ARG_MINUS = new Option(null, "minus", true, "After result do a minus operation");

    private static void printHelp(Options options) {
        HelpFormatter formatter = new HelpFormatter();
        PrintWriter pw = new PrintWriter(System.out);
        pw.println("MathAPP " + Math.class.getPackage().getSpecificationVersion());
        pw.println();
        formatter.printUsage(pw, 100, "java -jar MathAPP.jar [options] number1 number2");
        formatter.printOptions(pw, 100, options, 2, 5);
        pw.close();
    }

    public static void main(String[] args) {
        CommandLineParser clp = new DefaultParser();

        Options options = new Options();
        options.addOption(ARG_ADD);
        options.addOption(ARG_SUB);
        options.addOption(ARG_MUL);
        options.addOption(ARG_DIV);
        options.addOption(ARG_MINUS);

        try {
            CommandLine cl = clp.parse(options, args);

            if (cl.getArgList().size() < 2) {
                printHelp(options);
                System.exit(-1);
            }

            int a = 0;
            int b = 0;
            try {
                a = Integer.parseInt(cl.getArgList().get(0));
                b = Integer.parseInt(cl.getArgList().get(1));
            } catch (Exception e) {
                printHelp(options);
                e.printStackTrace();
                System.exit(-1);
            }

            if(cl.hasOption(ARG_ADD.getLongOpt())) {
                System.out.println(a + b);
            } else if(cl.hasOption(ARG_SUB.getLongOpt())) {
                System.out.println(a - b);
            } else if(cl.hasOption(ARG_MUL.getLongOpt())) {
                System.out.println(a * b);
            } else if(cl.hasOption(ARG_DIV.getLongOpt())) {
                System.out.println(a / b);
            } else {
                printHelp(options);
            }

            if(cl.hasOption(ARG_MINUS.getLongOpt())) {
                String val = cl.getOptionValue(ARG_MINUS.getLongOpt());
                int sum = a - (Integer.parseInt(val));
                System.out.println(sum);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}