java - 给定一个 calendar.week_of_year，如何获取一周的开始和结束日期？

Question

给定 week_of_year，我如何获取该周的开始和结束日期？

示例:假设日期是 2017 年 1 月 1 日。

Calendar calendar = Calendar.getInstance();
// Let's assume that we've set calendar to Jan/1/2017.
Integer week_of_year = calendar.get(Calendar.WEEK_OF_YEAR)

week_of_year 将返回 1。据推测，第 1 周是 Jan/1/2017 到 Jan/7/2017 之间的任何时间。

如何反向查找 week_of_year=1 并获取 Jan/7/2017 到 Jan/6/2017 的最小值/最大值？或任何其他有效的 week_of_year 值。

Answer 1

        SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.WEEK_OF_YEAR, 1);
        cal.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
        System.out.println("Start Date: " + sdf.format(cal.getTime()));
        cal.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY);
        System.out.println("End Date: " + sdf.format(cal.getTime()));