How do I white list a phrase before validating it for special characters using Java Regex package-CodePudding

Hey I need to bypass the validation for substring whiteList in the string str but the rest of the string needs to be validated for the special characters '<', '>', '$', '#', '@'.

Assuming that substring is not repeated anywhere else in the main string.

This is the main string String str = "blah blah blah X has paid $8,894 to the shop owner blah blah blah"

This is the sub string "String whiteList = "x has paid $8,894 to the shop owner";

current validation for the main string boolean specialChar = Pattern.compile("<|>|\\$|#|@", Pattern.CASE_INSENSITIVE).matcher(str).find();

The substring whiteList contains $ which should not be validated and should return false.

I am looking for a solution using regular expression if its possible. Any help would be greatly appreciated. Thanks~

CodePudding user response：

I do not know about java. Just curious because of the regex involvement.

What about this using this regex:

[^\s<>$#@] \shas paid [\d,]  to the shop owner

It will only catch the required part from the main string
The variable part in this match is the word before has for which we can use ^ to avoid such chars presence
Input like blah blah blah ><$ has paid 8,894 to the shop owner blah blah blah will be no match for the substring.

P.S. sorry if this is not relevant.

CodePudding user response：

Just go around it:

String stringToCheck;
int pos = str.indexOf(whiteList);
if (pos >= 0) {
    stringToCheck =
        str.substring(0, pos)   str.substring(pos   whiteList.length());
} else {
    stringToCheck = str;
}

boolean specialChar =
    Pattern.compile("[<>$#@]").matcher(stringToCheck).find();