import joptsimple.OptionParser; import joptsimple.OptionSet; import joptsimple.OptionSpec; public class CommandLineParser { public static void main(String[] args) throws Exception { OptionParser parser = new OptionParser(); OptionSpec<Integer> portOption = parser.accepts("port") .withRequiredArg() .ofType(Integer.class) .defaultsTo(8080) .describedAs("server port"); OptionSpec<String> configFileOption = parser.accepts("config") .withRequiredArg() .ofType(String.class) .describedAs("config file path"); OptionSet options = parser.parse(args); if (options.has(portOption)) { int port = options.valueOf(portOption); System.out.println("Server port: " + port); } if (options.has(configFileOption)) { String configFile = options.valueOf(configFileOption); System.out.println("Config file: " + configFile); } } }