I have set up a regex to match couple of strings. When I use this regex in Apex class directly as string, it works correctly. However when i use the same regex from a custom Text field in Custom Settings it gives below error
System.StringException: Invalid regex: Illegal character range near index 8 [\d\s-#+@]{7,}
Tried to find a way, however all in vain.
Regex I am using is [\\d\\s-#+@]{7,}
Can anybody assist here in resolving this.
Regards Nitesh
When you're writing Apex Code, the compiler interprets \ as an escape meant for the source code. The Pattern class interprets \ as an escape character as well. Therefore, when you use [\\d\\s-#+@]{7,}, that means that you're actually passing in literal \ characters. It becomes interpreted as:
[ \ d \ s-# + @ ]{7,}
| 2 3 2 4 5 6 | 7
\-------1-------/
1: Match any character in this set
2: Match a literal "\"
3: Match a literal "d"
4: Match the range "s" through "#"
5: Match a literal "+"
6: Match a literal "@"
7: Match at least 7 times consecutively
The problem here is #4: "s" comes after "#", so the compiler won't allow it. It would allow "#" through "s", but this is not your intent.
When you're using data from a string (a label, custom setting, user input, etc), you do not escape the \, because you're not compiling Apex Code. The regex, as you've written it, would look like the following source code:
Pattern p = Pattern.compile('[\\\\d\\\\s-#+@]{7,}');
To fix this, remove the escape characters that you used to get them in the source code.
The custom setting's value should be:
[\d\s-#+@]{7,}
