I have tried with [\s]+$ and (?:$|\s)+$ but i don't get the desired output.
What i am looking for is
String str ="this is a string ending with multiple newlines\n\n\n"
the new line can be : \n or \r or \r\n depending on OS so we use \s+ here.
I need to find all the newline chars from end of the string and i have to use it in Java Code
The point is that \s, in Java, matches any non-Unicode whitespace by default (it matches any Unicode whitespace if you use (?U)\s).
You can use
String regex = "\\R+$";
String regex = "\\R+\\z";
See the regex demo.
If you need to get each individual line break sequence at the end of string, you can use
String regex = "\\R(?=\\R*$)";
See this regex demo.
These patterns mean
\R+ - one or more line break sequences$ - at the end of the string (\z matches the very end of string and will work identically in this case)\R(?=\R*$) - any line break sequence followed with zero or more line break sequences up to the end of the whole string.