Help constructing a Pattern

Question

I have a string that looks like
oneof(val1,val2,val3,...)
where val2 and on (and the comma) are optional.
I need to construct a Pattern that matches this
and allows me to get the values (without the
separating commas).
The static part of the input string is easy to match:
Pattern p = Pattern.compile("oneof\\(\\)");
But I can't figure out the 'val1,val2,...' part.
Something like:
([^,]+)(,[^,])+
But that would retain the comma in the capturing
group. There is the (?:) non-capturing group but
I don't know how to incorporate that.
As an aside question. I can get an individual match
with matcher.group(n) but how do I determine how
many groups were matched (valid values for n)?
matcher.groupCount() isn't it, I don't think, since it
applies to the pattern and not the matched strings.
Thanks for your help.

Answer 1

import java.util.regex.*;
public class Zy
    public static void main(String[] args)
        Pattern p = Pattern.compile("^oneof\\(val1(,val(\\d))*\\)");
        Matcher m = p.matcher("oneof(val1,val2,val3)");
        boolean b = m.matches();
        if (b = true)
            System.out.println("Input val count: " + m.group(2));
}