How to check if a String contains another String in a case insensitive manner in Java?

Question

Say I have two strings,

String s1 = \"AbBaCca\";
String s2 = \"bac\";

I want to perform a check returning that s2 is contained

Answer 1

You can use

org.apache.commons.lang3.StringUtils.containsIgnoreCase("AbBaCca", "bac");

The Apache Commons library is very useful for this sort of thing. And this particular one may be better than regular expressions as regex is always expensive in terms of performance.