String contains any but one character

Question

I want to check if a String contains a } with any character in front of it except \. As far as I know I can use . as a metacharacter in aString.contains(...) to allow any character at that position but I don’t know how to create something like a blacklist: aString.contains(“.(except ‘\‘)}“Is that possible without creating an own method?

Answer 1

You need regex (well technically you don't need regex, but it's the best way):

if (aString.matches(".*(?<!\\\\)}.*"))

This regex says the string should be made up as follows

• .* zero or more of any character
• (?<!\\\\) the previous char is not a backslash
• } a curly right bracket
• .* zero or more of any character

This also works for the edge case of the first char being the curly bracket.

See live demo.