java - 从周数查找一周的开始结束日期

Question

我使用 servlet 和 JSP 构建一个 Web 应用程序，并在 Servlet 内计算星期几:

 private int findWeekNumber(String myDate) 
    throws ParseException{
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
        Date date;
        date = df.parse(myDate);
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        int week = cal.get(Calendar.WEEK_OF_YEAR);
        System.out.println("week number is:" + week);

        return week;
    }

然后我将周保存到我的数据库中。然后我从数据库中检索周。如何从 week 获取一周的开始 - 结束日期(周开始于星期一)？假设 weekNumber 是 30，我想计算 20/07/2015 - 26/07/2015。相同的功能是here

Answer 1

Java 8 版本

LocalDate week = LocalDate.now().with(ChronoField.ALIGNED_WEEK_OF_YEAR, yourWeekNumber);

LocalDate start = week.with(DayOfWeek.MONDAY);
LocalDate end = start.plusDays(6);
System.out.println(start +" - "+ end);