### Question:
DateUtils { public static String getSimpleFormatDate(Date date) { return getFormatedDate(date, defaultDayFormat); }  static int getWeekByDate(Date date); static String getCNDefaultDate(); static String getCNWeek(int week); static String getFormatedDate(Date date); static String getFormatedDate(Date now, String format); static String getSimpleFormatDate(Date date); static String getSimpleFormatedDateNow(); static String getStandTime(); static Date parseStringToDate(String date); static Date parseStringToDate(String date, String format);  }### Answer:
@Test public void testGetSimpleFormatDate() { String strDate = DateUtils.getSimpleFormatDate(new Date()); Assert.assertEquals(strDate + "应该为'yyyy-MM-dd'字符串！" + 10, 10, strDate.length()); strDate = DateUtils.getSimpleFormatDate(null); Assert.assertNull("DateUtils.getSimpleFormatDate(null)应该返回null！", strDate); }