“No match Found” when using matcher's group method

Question

I\'m using Pattern/Matcher to get the response code in an HTTP response. groupCount returns 1, but I get an exception when trying to g

Answer 1

pattern.matcher(input) always creates a new matcher, so you'd need to call matches() again.

Try:

Matcher m = responseCodePattern.matcher(firstHeader);
m.matches();
m.groupCount();
m.group(0); //must call matches() first
...

Answer 2

You are constantly overwriting the matches you got by using

System.out.println(responseCodePattern.matcher(firstHeader).matches());
System.out.println(responseCodePattern.matcher(firstHeader).groupCount());

Each line creates a new Matcher object.

You should go

Matcher matcher = responseCodePattern.matcher(firstHeader);
System.out.println(matcher.matches());
System.out.println(matcher.groupCount());