JAVA获取一个月的开始与结束时间以及两个日期相差几个月

╰半橙微兮° 2022-05-10 15:46 965阅读 0赞

# 一、一个月的开始与结束时间代码如下 #

/**
         * 获取指定月的开始日期
         * @param currentDate
         * @return
         */
        public static Date getStartDate(String currentDate){
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            Calendar c = Calendar.getInstance();
            try {
                c.setTime(sdf.parse(currentDate));
                c.add(Calendar.MONTH, 0);
                //设置为1号,当前日期既为本月第一天
                c.set(Calendar.DAY_OF_MONTH, 1);
            } catch (ParseException e) {
                e.printStackTrace();
            }
            return c.getTime();
        }
    
        /**
         * 获取指定月的结束日期
         * @param currentDate
         * @return
         */
        public static Date getEndDate(String currentDate){
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            Calendar c = Calendar.getInstance();
            try {
                c.setTime(sdf.parse(currentDate));
                c.set(Calendar.DAY_OF_MONTH, c.getActualMaximum(Calendar.DAY_OF_MONTH));
                c.set(Calendar.HOUR_OF_DAY, 23);
                c.set(Calendar.MINUTE, 59);
                c.set(Calendar.SECOND, 59);
            } catch (ParseException e) {
                e.printStackTrace();
            }
            return c.getTime();
        }

# 二、两个日期相差几个月 #

/**
         * 获取两个日期相差几个月
         * @param start
         * @param end
         * @return
         */
        public static int getMonth(Date start, Date end) {
            if (start.after(end)) {
                Date t = start;
                start = end;
                end = t;
            }
            Calendar startCalendar = Calendar.getInstance();
            startCalendar.setTime(start);
            Calendar endCalendar = Calendar.getInstance();
            endCalendar.setTime(end);
            Calendar temp = Calendar.getInstance();
            temp.setTime(end);
            temp.add(Calendar.DATE, 1);
            int year = endCalendar.get(Calendar.YEAR) - startCalendar.get(Calendar.YEAR);
            int month = endCalendar.get(Calendar.MONTH) - startCalendar.get(Calendar.MONTH);
            if ((startCalendar.get(Calendar.DATE) == 1)&& (temp.get(Calendar.DATE) == 1)) {
                return year * 12 + month + 1;
            } else if ((startCalendar.get(Calendar.DATE) != 1) && (temp.get(Calendar.DATE) == 1)) {
                return year * 12 + month;
            } else if ((startCalendar.get(Calendar.DATE) == 1) && (temp.get(Calendar.DATE) != 1)) {
                return year * 12 + month;
            } else {
                return (year * 12 + month - 1) < 0 ? 0 : (year * 12 + month);
            }
        }

# 三、测试代码 #

public static void main(String[] args) throws ParseException{
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            String startDate = "2018-10-15 00:00:00";
            String ednDate = "2019-11-10 23:59:59";
            Date sdate = getStartDate(startDate);
            Date edate = getEndDate(startDate);
            System.out.println("开始时间：" + sdf.format(sdate));
            System.out.println("结束时间：" + sdf.format(edate));
            int month = getMonth(sdf.parse(startDate), sdf.parse(ednDate));
            System.out.println("两者之间相差：" + month);
        }