java常用时间处理方法收藏

朴灿烈づ我的快乐病毒、 2022-04-24 11:06 214阅读 0赞

/**
         * 得到几天前的时间
         *
         * @param d
         * @param day
         * @return
         */
        public static String getDateBefore(Date d, int day) {
            SimpleDateFormat dft = new SimpleDateFormat("yyyy-MM-dd");
            Calendar now = Calendar.getInstance();
            now.setTime(d);
            now.set(Calendar.DATE, now.get(Calendar.DATE) - day);
            return dft.format(now.getTime());
        }
    
        /**
         * 描述:获取上个月的最后一天.
         *
         * @return
         */
        public static String getLastMaxMonthDate() {
            SimpleDateFormat dft = new SimpleDateFormat("yyyy-MM-dd");
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(new Date());
            calendar.add(Calendar.MONTH, -1);
            calendar.set(Calendar.DAY_OF_MONTH,                     
            calendar.getActualMaximum(Calendar.DAY_OF_MONTH));
            return dft.format(calendar.getTime());
        }
    
        /**
         * 获取上几个月
         *
         * @return
         */
        public static String getLastMonth(Integer n) {
            Calendar cal = Calendar.getInstance();
            cal.add(cal.MONTH, -n);
            SimpleDateFormat dft = new SimpleDateFormat("yyyy-MM");
            String lastMonth = dft.format(cal.getTime());
            return lastMonth;
        }
    
        /**
         * 获取上一个月月数
         *
         * @return
         */
        public static Integer lastMonth() {
            Calendar cal = Calendar.getInstance();
            cal.add(cal.MONTH, -1);
            SimpleDateFormat dft = new SimpleDateFormat("M");
            Integer lastMonth = Integer.parseInt(dft.format(cal.getTime()));
            return lastMonth;
        }
    
        //获取前几月的天数
        public static Integer getDaysOfMonth(Integer n) {
            Calendar calendar = Calendar.getInstance();
            calendar.setTime(new Date());
            calendar.add(Calendar.MONTH, -n);
            return calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
        }
    
        /**
         * 通过时间秒毫秒数判断两个时间的间隔
         * @param time1
         * @param time2
         * @return
         */
        public static int differentDaysByMillisecond(String time1,String time2)
        {
            if(time1.trim().indexOf(" ") >0 || time1.indexOf(":")>0){
                time1 = time1.substring(0,time1.indexOf(" "));
            }
            if(time2.trim().indexOf(" ") >0 || time2.indexOf(":")>0){
                time2 = time2.substring(0,time2.indexOf(" "));
            }
            SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd");
            try{
                Date date1 = sf.parse(time1+" 00:00:00");
                Date date2 = sf.parse(time2+" 00:00:00");
                int days = Math.abs((int) (( date1.getTime()-date2.getTime()) /     
      (1000*3600*24)));
                return days;
            }catch (Exception e){
                System.out.println(e.getMessage());
                return 0;
            }
        }