I have a regular expression that I want to use to pull ID's out of a JSON string. The expression itself appears to work fine based on the data I've given it, so that's good. Unfortunately, it involves more than one non-capturing group ("(?:)"), and that seems to break Apex with the dreaded "Invalid regex at index 9." Is there actually a 1 non-capture group limit in Apex's regex flavor or is there something else wrong with this? I wasn't able to find any documentation on such a limit, so i'm inclined to think that there is some other error in my regex, but I can't find it!

Just for completeness, here's an example that is failing on my sandbox.

pattern myPattern = pattern.compile('^(?:.*)(?:{"id":)$'); 
matcher myMatcher = myPattern.matcher('{"user":{"id":11111,"userName":');
System.assert(myMatcher.matches() && myMatcher.hitEnd());

if(myMatcher.matches())
{
    system.debug(myMatcher.group(1));
}

*** bolded for easier skimming**

I have a regular expression that I want to use to pull ID's out of a JSON string. The expression itself appears to work fine based on the data I've given it, so that's good.

^(?:.*)(?:{"id":)(\d+)(?:.*)$

Unfortunately, it involves more than one non-capturing group ("(?:)"), and that seems to break Apex with the dreaded "Invalid regex at index 9." Is there actually a 1 non-capture group limit in Apex's regex flavor or is there something else wrong with this? I wasn't able to find any documentation on such a limit, so i'm inclined to think that there is some other error in my regex, but I can't find it!

Just for completeness, here's an example that is failing on my sandbox.

pattern myPattern = pattern.compile('^(?:.*)(?:{"id":)$'); 
matcher myMatcher = myPattern.matcher('{"user":{"id":11111,"userName":');
System.assert(myMatcher.matches() && myMatcher.hitEnd());

if(myMatcher.matches())
{
    system.debug(myMatcher.group(1));
}

*** bolded for easier skimming**