java 获取指定日期

//可以设置指定那一天:例如,最近一周,参数传入-7,最近一月,参数传入-30...
private String getBeginDate(int date) throws ParseException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Date beginTime = new Date();
        Calendar beginCalendar = Calendar.getInstance();
        beginCalendar.setTime(beginTime);
        beginCalendar.add(Calendar.DATE, date);
        return sdf.format(beginCalendar.getTime());
    }