I want to check a string (like the one below) for non-integers and non-whitespace:

1. String data = "9 11 6 8 4 14 3 13 5 7 10 12 16 2 15 1";

I want to pass the results of the following regex to a boolean like this:

1. String[] is_integers = match(data, "[\D\W]");
2. if (is_integers != null) {
3.     (there are non-digits and non-whitespace in the string...)
   

But that throws an error in Processing, and I can only get a result with a regex (e.g.) like this:

1. match(data, "[^0-9 \n\r]");
   

When I use the (Java) character classes \D and \W in my regex I get 'unexpected char' 'D' and 'W' - why?