java格式话时间报错java cannot format given object as a date

String MonthYear = null;    
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("mm/yyyy");    
String dateformat = "2012-11-17T00:00:00.000-05:00"
MonthYear = simpleDateFormat.format(dateformat);    
System.out.println(MonthYear);

DateFormat outputFormat = new SimpleDateFormat("yyyy/MM");
        DateFormat inputFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.US);
        Date date = null;
        String inputText = "2012-11-17";
        try {
            date = inputFormat.parse(inputText);
        }catch (Exception e){
            e.printStackTrace();
        }
        String outputText = outputFormat.format(date);
        System.out.println(outputText);