@Pattern("^\\[")
Does not work.
Sample inputs:
Welcome[Hello - Pass
Welcome[ - Pass
[Welcome - Fail
- Pass
@Pattern("^(?!\\[).*")
was suggested from stackoverflow.
But when inserting new line char (\n) it doesn't seems working
public final static String FREE_TEXT_FIELD_VALIDATION_PATTERN = "^(?!\\[).*";
@Pattern(regexp = FREE_TEXT_FIELD_VALIDATION_PATTERN, message = FREE_TEXT_FIELD_VALIDATION_ERROR)
public String ruleDescription;
^\[.*$
^ = start of string
\[ = escaped '[' character
.* = zero or more of any character except newline
Welcome[Hello - Fail
Welcome[ - Fail
[Welcome - Pass
You can test here https://regexr.com/
If you want to match anything who NOT START with [ but allow line break
^(?!(\[))\w+((.|\n)*)$
Welcome[Hello - Pass
Welcome[ - Pass
[Welcome - Pass
[Welcome
test. - PASS
^(?!(\[))\w+((.|\n)*)$|^$
We add |^$ for allow empty string
| is used to denote alternates this|that.