Talend Equivalent for Index Function in Datastage

    package routines;

    public class UserString {

      public static int Index(String string, String substring, Integer instance) {
        int index = -1;
        if (string == null) {
          return 0;
        }
        if (substring == null) {
          return 0;
        }
        if (substring.equals("")) {
          return 1;
        }
        if (instance == null) {
          throw new UnsupportedOperationException("Instance is supposed to be NOT NULL!!");
        }
        if (!string.contains(substring)) {
          return 0;
        }

        index = string.indexOf(substring, 0);

        while (--instance > 0 && index != -1) {
          index = string.indexOf(substring, index + 1);
        }

        return ++index;
      }
    }