Using the regular expression
\s+$, you can replace all trailing space characters (includes space and tab characters) with nothing (
final String text = " foo "; System.out.println(text.replaceFirst("\\s+$", ""));
Here's a breakdown of the regex:
\s– any whitespace character
+– match one or more of the previous token; i.e., match one or more whitespace character
$– the end of the string
Thus, the regular expression will match as much whitespace as it can that is followed directly by the end of the string: in other words, the trailing whitespace.
The investment into learning regular expressions will become more valuable, if you need to extend your requirements later on.