Mutually exclusive options using Apache Commons CLI

Question

I can create 2 mutually exclusive options using the following:

Option a = OptionBuilder.create("a");
Option b = OptionBuilder.create("b");

OptionGroup optgrp = new OptionGroup();
optgrp .setRequired(true);
optgrp .addOption(a);
optgrp .addOption(b);

The above will force the user to provide either option a or option b.

But if I have a third option, c:

Option c = OptionBuilder.create("c");

is it possible to create mutually exclusive options such that:

Either:

1. Option a must be provided OR
2. Both options b and c must be provided

I couldn't see a way to do it using OptionGroup?

Labelle

Answer 1

As a workaround to this, I implemented the following, not ideal, but..

public static void validate(final CommandLine cmdLine) {
   final boolean aSupplied = cmdLine.hasOption(A);

   final boolean bAndCSupplied = cmdLine.hasOption(B) && cmdLine.hasOption(C);

   final boolean bOrCSupplied = !bAndCSupplied && (cmdLine.hasOption(B) || cmdLine.hasOption(C));

   if ((aSupplied && bAndCSupplied) || (!aSupplied && !bAndCSupplied)
      || (aSupplied && bOrCSupplied )) {
          throw new Exception(...);
   }
}

Labelle

Yes, I don't think functionality in commons-cli goes that far, but on the other hand it would add a lot of very complicated code for a few cases that can easily be dealt with outside of the library like you did. – Mutiny

Answer 2

I think a possible workaround could be defining both option b and c in one option. If they are flags, they could both be true, or both be false, but no different combination is possible depending of the rules you set. So I guess they have values. So you could define an option which have two values.

Roehm

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