Rory Rory - 11 months ago 52
Java Question

Apache Commons CLI - ordering help options?

I'm using the Apache Commons CLI. By default it orders help options on the command line alphabetically by key. So, what appears is:

-csv
-ip
-msisdn
-xml


But I want to order them as follows:

-csv
-xml
-ip
-msisdn


I know that there is a OptionFormatter class you can use and pass to the HelpFormatter, but can't see any examples on how to use it for my purposes above (http://www.marko.homeunix.org/programming/java/commons-cli/api/org/apache/commons/cli/HelpFormatter.OptionComparator.html).

Just wondering has anyone done anything similar?

Thanks

Answer Source

Currently it is not supported. But it is an open source so, you know what to do...

From the source code:

    private static class OptionComparator
    implements Comparator {

    /**
     * <p>Compares its two arguments for order. Returns a negative 
     * integer, zero, or a positive integer as the first argument 
     * is less than, equal to, or greater than the second.</p>
     *
     * @param o1 The first Option to be compared.
     * @param o2 The second Option to be compared.
     *
     * @return a negative integer, zero, or a positive integer as 
     * the first argument is less than, equal to, or greater than the 
     * second.
     */
    public int compare(Object o1, Object o2)
    {
        Option opt1 = (Option)o1;
        Option opt2 = (Option)o2;

        return opt1.getKey().compareToIgnoreCase(opt2.getKey());
    }
}

You can override the default comparator and define the order you want.