Question

这让我疯了！

我到处搜索过，例如找到了这个问题：How to get dates of a week (I know week number)?

但是我无法在我的实现中使用它（在NEXUS 7上的ANDROID API19上）：

public Pair<String,String> getWeekRange(int year, int week_no) {

    Calendar cal = Calendar.getInstance();
    cal.set(Calendar.YEAR, year);
    cal.set(Calendar.WEEK_OF_YEAR, week_no);

    cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
    Date monday = cal.getTime();
    cal.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
    Date sunday = cal.getTime();

    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
    return new Pair<String,String>(sdf.format(monday), sdf.format(sunday));
}

对于getWeekRange(2014, WEEK)的任何通话，它总是给我第2周的日期范围（恰好是今天的当前周数）??

日历似乎是一个非常令人困惑的课程，必须有一些我不理解的东西。但是根据文档，YEAR，WEEK_OF_YEAR和DAY_OF_WEEK应该足以让我设置。

Some test data:
01-10 18:28:54.730: V/JSON(24503): Week 1/2014 is date range:2014-01-06 to 2014-01-12
01-10 18:28:54.730: V/JSON(24503): Week 2/2014 is date range:2014-01-06 to 2014-01-12
01-10 18:28:54.730: V/JSON(24503): Week 3/2014 is date range:2014-01-06 to 2014-01-12
01-10 18:28:54.730: V/JSON(24503): Week 4/2014 is date range:2014-01-06 to 2014-01-12
01-10 18:28:54.740: V/JSON(24503): Week 5/2014 is date range:2014-01-06 to 2014-01-12
01-10 18:28:54.740: V/JSON(24503): Week 1/2013 is date range:2013-01-07 to 2013-01-13
01-10 18:28:54.740: V/JSON(24503): Week 2/2013 is date range:2013-01-07 to 2013-01-13
01-10 18:28:54.740: V/JSON(24503): Week 3/2013 is date range:2013-01-07 to 2013-01-13
01-10 18:28:54.740: V/JSON(24503): Week 4/2013 is date range:2013-01-07 to 2013-01-13
01-10 18:28:54.740: V/JSON(24503): Week 5/2013 is date range:2013-01-07 to 2013-01-13

任何人都可以看到我的错误吗？任何帮助表示赞赏。

**编辑**

似乎代码在Windows上正常运行，这是一个孤立的Android问题。

Answer 1

写这个问题让我再一次阅读文档，只是在预感中我交换了顺序，所以函数现在看起来像这样：

public Pair<String,String> getWeekRange(int year, int week_no) {

    Calendar cal = Calendar.getInstance();

    cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
    cal.set(Calendar.YEAR, year);
    cal.set(Calendar.WEEK_OF_YEAR, week_no);
    Date monday = cal.getTime();

    cal.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
    cal.set(Calendar.YEAR, year);
    cal.set(Calendar.WEEK_OF_YEAR, week_no);
    Date sunday = cal.getTime();

    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
    return new Pair<String,String>(sdf.format(monday), sdf.format(sunday));
}

瞧，现在它给了我正确的日期......它必须是日历的内部实现，我不明白。

仍然不知道冗余线是否必要，但现在我很高兴它有效！

Answer 2

我认为使用Joda-Time进行此类操作要好得多：

public Pair<String,String> getWeekRange(int year, int week_no) {
    DateTime startOfWeek = new DateTime().withYear(year).withWeekOfWeekyear(week_no);

    DateTime endOfWeek = startOfWeek.plusDays(6);

    return new Pair<String,String>(startOfWeek.toString(), endOfWeek.toString());
}

Answer 3

在不导入Pair类

的情况下执行此操作

public  void getWeeksRangesDates(int y, int w) {
    Calendar cal = Calendar.getInstance();
    cal.set(Calendar.DAY_OF_MONTH, Calendar.MONDAY);
    cal.set(Calendar.YEAR, y);
    cal.set(Calendar.WEEK_OF_YEAR, w);
    Date date1 = cal.getTime();
    cal.add(Calendar.DATE, 6);
    Date date2 = cal.getTime();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
    Log.v("date1",sdf.format(date1));
    Log.v("date2", sdf.format(date2));  
}

如何在Android上查找给定周的日期范围？

3 个答案: