java – 尝试将日期YYYY-MM-DD转换为DD-MMM-YYYY,但该函数始终将

public String dateConvert(String D){

        SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-DD");
        SimpleDateFormat format2 = new SimpleDateFormat("dd-MMMM-yyyy");
        Date date = null;
        try {
            date = format1.parse(D);
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        String dateString = format2.format(date);
        dateString = dateString.replace("-"," "); 
        System.out.println(dateString);
        return ((dateString));
    }

然而,无论何时,我都会将这个月转换为1月.我不明白我哪里错了！