Java 输入两个日期，计算出期间的周数

左手的ㄟ右手 2023-07-06 08:57 8阅读 0赞

只要涉及到其他周的天，都算期间的周数：

static int calculate(Calendar c){
            int dayForWeek;
            if(c.get(Calendar.DAY_OF_WEEK) == 1){
                dayForWeek = 7;
            }else{
                dayForWeek = c.get(Calendar.DAY_OF_WEEK) - 1;}
            return dayForWeek;
        }
    
        static Calendar From(Calendar c){
            switch(calculate(c)){
                case 1:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)-0);
                    break;
                case 2:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)-1);
                    break;
                case 3:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)-2);
                    break;
                case 4:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)-3);
                    break;
                case 5:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)-4);
                    break;
                case 6:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)-5);
                    break;
                case 7:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)-6);
            }
            return c;
    
        }
    
        static Calendar To(Calendar c){
            switch(calculate(c)){
                case 1:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)+6);
                    break;
                case 2:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)+5);
                    break;
                case 3:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)+4);
                    break;
                case 4:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)+3);
                    break;
                case 5:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)+2);
                    break;
                case 6:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)+1);
                    break;
                case 7:c.set(Calendar.DAY_OF_YEAR, c.get(Calendar.DAY_OF_YEAR)+0);
            }
            return c;
    
        }
    
    
        static Long getResult(String startDate,String endDate) throws ParseException {
            Calendar c1 = Calendar.getInstance();
            Calendar c2 = Calendar.getInstance();
            SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
    
            c1.setTime(sdf.parse(startDate));
            c2.setTime(sdf.parse(endDate));
    
            long cc1=From(c1).getTimeInMillis()/(1000*3600*24);
            long cc2=To(c2).getTimeInMillis()/(1000*3600*24);
    
            return (cc2-cc1+1)/7;
        }

测试：

![20200217150517678.png][]

刚好一周：

public static void main(String[] args) throws ParseException {
    
            Long result = getResult("2020-02-10", "2020-02-16");
            System.out.println("涉及的周数为："+result);
    
        }

![20200217150635713.png][]

刚好两周：

public static void main(String[] args) throws ParseException {
    
            Long result = getResult("2020-02-10", "2020-02-23");
            System.out.println("涉及的周数为："+result);
    
        }

![2020021715073170.png][]

两周再多两天：

public static void main(String[] args) throws ParseException {
    
            Long result = getResult("2020-02-10", "2020-02-25");
            System.out.println("涉及的周数为："+result);
    
        }

![20200217150837480.png][]

[20200217150517678.png]: https://img-blog.csdnimg.cn/20200217150517678.png
[20200217150635713.png]: https://img-blog.csdnimg.cn/20200217150635713.png
[2020021715073170.png]: https://img-blog.csdnimg.cn/2020021715073170.png
[20200217150837480.png]: https://img-blog.csdnimg.cn/20200217150837480.png