I am writing a Java application that takes command line arguments which are processed using Apache Commons CLI with the GnuParser. For reasons that are not interesting to get into, I would like it to silently ignore unknown command line options instead of throwing a ParseException but I don't see a way to do that. I see that there is a stopAtNonOption boolean option on GnuParser.parse() but what I want is more like ignoreAtNonOption where it will keep processing options after encountering an unknown token.
I could implement my own parser to accomplish this but I'm surprised there isn't this functionality built in so I thought I'd check before going down that road.
Example code for what I'm talking about:
try {
CommandLine commandLine = parser.parse(options, args);
// stopAtNonOption set to true (below) is also not what I want
// CommandLine commandLine = parser.parse(options, args, true);
} catch (ParseException e) {
LOG.error("error parsing arguments", e);
throw new RuntimeException(e);
}
This works for me (other parsers can be derived, too):
public class ExtendedGnuParser extends GnuParser {
private boolean ignoreUnrecognizedOption;
public ExtendedGnuParser(final boolean ignoreUnrecognizedOption) {
this.ignoreUnrecognizedOption = ignoreUnrecognizedOption;
}
@Override
protected void processOption(final String arg, final ListIterator iter) throws ParseException {
boolean hasOption = getOptions().hasOption(arg);
if (hasOption || !ignoreUnrecognizedOption) {
super.processOption(arg, iter);
}
}
}