code: public static int indexOfIgnoreCase(final String str, final String searchStr) {// NOSONAR
  		if (searchStr.isEmpty() || str.isEmpty()) {
  			return str.indexOf(searchStr);
  		}
  		for (int i = 0; i < str.length(); ++i) {
  			if (i + searchStr.length() > str.length()) {
  				return -1;
  			}
  			int j = 0;
  			int ii = i;
  			while (ii < str.length() && j < searchStr.length()) {
  				char c = Character.toLowerCase(str.charAt(ii));
  				char c2 = Character.toLowerCase(searchStr.charAt(j));
  				if (c != c2) {
  					break;
  				}
  				j++;
  				ii++;
  			}
  			if (j == searchStr.length()) {
  				return i;
  			}
  		}
  		return -1;
  	}
docs: Return first postion ignore case, return -1 if not found