java - Android/Java - 以天为单位的日期差异

Question

我正在使用以下代码获取当前日期(格式为 12/31/1999，即 mm/dd/yyyy):

Textview txtViewData;
txtViewDate.setText("Today is " +
        android.text.format.DateFormat.getDateFormat(this).format(new Date()));

我还有另一个日期格式为:2010-08-25 (i.e. yyyy/mm/dd)，

所以我想找到日期与天数之间的差异，我如何找到天数之间的差异？

(换句话说，我想找出CURRENT DATE - yyyy/mm/dd 格式化日期之间的区别)

Answer 1

不是一个真正可靠的方法，最好使用JodaTime

  Calendar thatDay = Calendar.getInstance();
  thatDay.set(Calendar.DAY_OF_MONTH,25);
  thatDay.set(Calendar.MONTH,7); // 0-11 so 1 less
  thatDay.set(Calendar.YEAR, 1985);

  Calendar today = Calendar.getInstance();

  long diff = today.getTimeInMillis() - thatDay.getTimeInMillis(); //result in millis

这是一个近似值...

long days = diff / (24 * 60 * 60 * 1000);

要从字符串中解析日期，您可以使用

  String strThatDay = "1985/08/25";
  SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
  Date d = null;
  try {
   d = formatter.parse(strThatDay);//catch exception
  } catch (ParseException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } 


  Calendar thatDay = Calendar.getInstance();
  thatDay.setTime(d); //rest is the same....

不过，既然您确定日期格式...您也可以对其子字符串执行 Integer.parseInt() 以获得它们的数值。