Example

Consider the following CLI should be parsed:

mytool [--help --log <file>] [COMMAND]
COMMAND: clean|start
clean [-f|--force -d <directory>]
start [--return -d <workdir> -t <time>]

Then the corresponding declaration in Java might look like this:

class GlobalArgs
{
  @HelpOption
  boolean help; //help defaults to '--help'/'-h'
  @Option(longOption="log")
  File logFile;
  @Command(name="clean")
  CleanArgs clean;
  @Command(name="start")
  StartArgs start;

  static class CleanArgs
  {
    @Option
    boolean force; //options default to their field names
    @Option(shortOption='d', converter=DirectoryThatExists.class)
    File directory;
  }

  static class StartArgs
  {
    @Option(longOption="return")
    boolean returnImmediatly;
    @Option(shortOption='d', converter=DirectoryThatExists.class)
    File directory;
    @Option(shortOption='t', converter=IntegerValue.class)
    int time;
  }
}