通过Calendar计算两个日期之间相差的周次_calendar计算两天日期差

public static int getWeekByDate(Date startTime,Date endTime){
    Calendar startCalendar = Calendar.getInstance();
    startCalendar.setTime(startTime);

    Calendar endCalendar = Calendar.getInstance();
    endCalendar.setTime(endTime);

    //总周次
    int sumWeek = 0;
    //判断是否同一年
    if(startCalendar.get(Calendar.YEAR)==startCalendar.get(Calendar.YEAR)){
        //同一年，计算两个周次相减
        sumWeek = endCalendar.get(Calendar.WEEK_OF_YEAR) - startCalendar.get(Calendar.WEEK_OF_YEAR)+1;
    }else{
        //1.起始年剩余的周次
        //2.终止年的周次
        //3.中间经历过的年的总周次

        //1
        sumWeek+=(startCalendar.getWeeksInWeekYear()-startCalendar.get(Calendar.WEEK_OF_YEAR)+1);
        //2
        sumWeek+=endCalendar.get(Calendar.WEEK_OF_YEAR);
        //3
        int year = endCalendar.get(Calendar.YEAR)-startCalendar.get(Calendar.YEAR)-1;
        for (int i = 0; i < year; i++) {
            Calendar calendar = Calendar.getInstance();
            calendar.set(Calendar.YEAR,startCalendar.get(Calendar.YEAR)+i);
            sumWeek+=calendar.getWeeksInWeekYear();
        }
    }
    return sumWeek;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32