Calendar给当前时间增加日、时、分、秒

 public static void main(String[] args) {
        System.out.println("hour==" + addTime(new Date(), "hour", 4));
        System.out.println("minute==" + addTime(new Date(), "minute", 4));
        System.out.println("day==" + addTime(new Date(), "day", 4));
        System.out.println("second==" + addTime(new Date(), "second", 4));

    }

    public static Date addTime(Date date, String type, int time) {
        Date addDate = date;
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        if (StringUtils.equals(type, "hour")) {
            cal.add(Calendar.HOUR, time);
            addDate = cal.getTime();
            return addDate;
        }
        if (StringUtils.equals(type, "minute")) {
            cal.add(Calendar.MINUTE, time);
            addDate = cal.getTime();
            return addDate;
        }
        if (StringUtils.equals(type, "second")) {
            cal.add(Calendar.SECOND, time);
            addDate = cal.getTime();
            return addDate;
        }
        if (StringUtils.equals(type, "day")) {
            cal.add(Calendar.DAY_OF_MONTH, time);
            addDate = cal.getTime();
            return addDate;
        }

        return addDate;

    }