apache commons cli example

Application.java

import java.util.Arrays;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;

public class Application {
    public static void main(String[] args) {
        Options options = new Options();
        options.addOption(Option.builder("i")
            .longOpt("interactionId")
            .hasArg(true)
            .desc("interaction id ([REQUIRED] or use --clientId)")
            .required(false)
            .build());
        options.addOption(Option.builder("c")
            .longOpt("clientId")
            .hasArg(true)
            .desc("client id ([REQUIRED] or use --interactionId)")
            .required(false)
            .build());
        options.addOption(Option.builder("f")
            .longOpt("file")
            .hasArg(true)
            .desc("[REQUIRED] one log-file or list of many log-files as input for log-parser")
            .numberOfArgs(Option.UNLIMITED_VALUES)
            .required()
            .build());

        CommandLineParser parser = new DefaultParser();
        CommandLine cmd = null;
        try {
            cmd = parser.parse(options, args);

            if (cmd.hasOption("c")) {
                String clientId = cmd.getOptionValue("c");
                System.out.println("We have --clientId option = " + clientId);
                if (cmd.hasOption("i")) {
                    System.out.println("( --interactionId option is omitted because --clientId option is defined)");
                }
            } else if (cmd.hasOption("i")) {
                String interactionId = cmd.getOptionValue("i");
                System.out.println("We have --interactionId option " + interactionId);
                if (cmd.hasOption("c")) {
                    System.out.println("( --clientId option is omitted because --interactionId option is defined)");
                }
            } else {
                System.out.println("please specify one of the command line options: "
                    + " -c,--c <arg>             client id\n"
                    + "OR\n"
                    + " -i,--interaction <arg>   interaction id");
            }
            if (cmd.hasOption("f")) {
                String[] files = cmd.getOptionValues("f");
                System.out.println("Number of files: " + files.length);
                System.out.println("FileName(s): " + String.join(", ", Arrays.asList(files)));
            }
        } catch (ParseException pe) {
            System.out.println("Error parsing command-line arguments!");
            System.out.println("Please, follow the instructions below:");
            HelpFormatter formatter = new HelpFormatter();
            formatter.printHelp( "Log messages to sequence diagrams converter", options );
            System.exit(1);
        }
    }
}