Java regex error - Look-behind group does not have an obvious maximum length

Question

I get this error:

java.util.regex.PatternSyntaxException: Look-behind group does not have an
    obvious maximum length near index 22
([a-z])(?!.*\\1)(?

        

Answer 1

To avoid this error, you should replace + with a region like {0,10}:

([a-z])(?!.*\1)(?