public static String getString(long date, String format) {
    Date d = new Date(date);
    return getString(d, format);
  }
@Test
  public void getString_dateSignature() throws ParseException {
    String expectedDate = "15/05/2012";
    String format = "dd/MM/yyyy";
    Date date = new SimpleDateFormat(format).parse(expectedDate);
    assertEquals(expectedDate, DateUtils.getString(date, format));
  }