爪哇国新游记之三十一----日期时间与字符串间的转化

Date date = new Date();
Format formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String dateString=formatter.format(date);

String dateStr1="20141216";
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
Date date1 = sdf.parse(dateStr1);

    public static String getDateBefore(Date d, int day) {
        Calendar now = Calendar.getInstance();
        now.setTime(d);
        now.set(Calendar.DATE, now.get(Calendar.DATE) - day);
        
        Format formatter = new SimpleDateFormat("yyyy-MM-dd");
        return formatter.format(now.getTime());
    }