比较日期是否早于 24 小时

I am trying to compare two calendars in java to decide if one of them is >= 24 hours ago. I am unsure on the best approach to accomplish this.

            //get todays date
            Date today = new Date();
            Calendar currentDate = Calendar.getInstance();
            currentDate.setTime(today);

            //get last update date
            Date lastUpdate = profile.getDateLastUpdated().get(owner);
            Calendar lastUpdatedCalendar = Calendar.getInstance();
            lastUpdatedCalendar(lastUpdate);

            //compare that last hotted was < 24 hrs ago from today?

推荐答案

你可以使用 Date.getTime()，这里是一个例子:

public final static long MILLIS_PER_DAY = 24 * 60 * 60 * 1000L;
public static void main(String args[]) throws Exception {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    Date date1 = sdf.parse("2009-12-31");
    Date date2 = sdf.parse("2010-01-31");

    boolean moreThanDay = Math.abs(date1.getTime() - date2.getTime()) > MILLIS_PER_DAY;

    System.out.println(moreThanDay);
}