String numberTo = "+1-     801-351-9512";

+18013519502

static String removeWhiteSpaceAndDashFromNumberAndPrependChar(String numberTO) {
  numberTO = StringUtils.deleteWhitespace(numberTO);
  numberTO = StringUtils.remove(numberTO, "-");
  numberTO = StringUtils.prependIfMissing(numberTO, "+", "+");

  return numberTO;
}

static String removeWhiteSpaceAndDashFromNumberAndPrependChar(String number) {
    return "+" + number.replaceAll("[+\-\s]+", "");
}

String numberTo = "+1- 801-351-9512";
numberTo = "+" + numberTo.replaceAll("\D", "");

private static final Pattern pattern = Pattern.compile("\D");

public static void main(String[] args) {
    String value = "+1- 801-351-9512";

    System.out.println("+" + pattern.matcher(value).replaceAll(""));
}

StringUtils.join("+" + CharMatcher.inRange('0', '9').retainFrom(value));

value = "+" + value.replaceAll("[^A-Za-z0-9]", "");