Java Argument Parser V2

import java.util.Map;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;
import java.util.InputMismatchException;

public class ArgParser{

    public static void main(String[] args) {
        Map<String, List<String>> parsedArgs = ParseArgs(args);
        Map<String, String[]> rules = new HashMap<String, String[]>();

        rules.put("filmes", new String[]{"nome_ator1", "nome_ator2", "decada"});
        rules.put("episodios", new String[]{"nome_ator", "titulo_serie"});
        rules.put("generos", new String[]{"nome_ator"});

        ValidateArgs(parsedArgs, rules);

        for(Map.Entry<String, List<String>> arg: parsedArgs.entrySet()) {
            System.out.println(arg.getKey());

            for(String subArg: arg.getValue())
                System.out.println("\t" + subArg);
        }
    }

    public static Map<String, List<String>> ParseArgs(String[] args) {
        Map<String, List<String>> result = new HashMap<String, List<String>>();
        List<String> subArgs = null;

        for(String arg: args)
            if(arg.startsWith("-"))
                result.put(arg.substring(1), subArgs = new ArrayList<String>());
            else if(subArgs != null)
                subArgs.add(arg);
            else
                throw new IllegalArgumentException("Argumento Invalido!");

        return result;
    }

    public static void ValidateArgs(Map<String, List<String>> args, Map<String, String[]> rules) {
        for(Map.Entry<String, String[]> rule: rules.entrySet()) {
            List<String> subArgs = args.get(rule.getKey());
            String[] argNames = rule.getValue();

            if(subArgs == null || subArgs.size() != argNames.length) {
                String Msg = String.format("O parametro <%s> espera %d subargumentos.\nModo de uso: <-%s>"
                                           , rule.getKey(), argNames.length, rule.getKey());

                for(String str: argNames)
                    Msg += " <" + str + ">";

                throw new InputMismatchException(Msg);
            }
        }
    }
}