jetbrick-commons/src/main/java/jetbrick/lang/StringUtils.java
public static int indexOfIgnoreCase(String s, String substr) {
        return indexOfIgnoreCase(s, substr, 0, s.length());
    }
public static int indexOfIgnoreCase(String s, String substr) {
        return indexOfIgnoreCase(s, substr, 0, s.length());
    }
Finds first index of a substring in the given source string with ignored case.

@param s    source string for examination
@param substr   substring to find

@return index of founded substring or -1 if substring is not found
@see #indexOfIgnoreCase(String, String, int)