在Java 8中，你可以使用与Joda Time非常相似的LocalDate。

只需结合YEAR属性检查DAY_OF_YEAR

boolean isSameDay = 
firstCal.get(Calendar.YEAR) == secondCal.get(Calendar.YEAR) &&
firstCal.get(Calendar.DAY_OF_YEAR) == secondCal.get(Calendar.DAY_OF_YEAR)

编辑:

现在我们可以使用Kotlin扩展函数的强大功能

fun Calendar.isSameDay(second: Calendar): Boolean {

    return this[Calendar.YEAR] == second[Calendar.YEAR] && this[Calendar.DAY_OF_YEAR] == second[Calendar.DAY_OF_YEAR]
}

fun Calendar.compareDatesOnly(other: Calendar): Int {

    return when {
        isSameDay(other) -> 0
        before(other) -> -1
        else -> 1
    }
}

这里有一个来自这个博客的解决方案:http://brigitzblog.blogspot.com/2011/10/java-compare-dates.html

long milliseconds1 = calendar1.getTimeInMillis();
long milliseconds2 = calendar2.getTimeInMillis();
long diff = milliseconds2 - milliseconds1;
long diffDays = diff / (24 * 60 * 60 * 1000);
System.out.println("Time in days: " + diffDays  + " days.");

也就是说，你可以看到以毫秒为单位的时间差是否小于一天的长度。

public static Date getZeroTimeDate(Date fecha) {
    Date res = fecha;
    Calendar calendar = Calendar.getInstance();

    calendar.setTime( fecha );
    calendar.set(Calendar.HOUR_OF_DAY, 0);
    calendar.set(Calendar.MINUTE, 0);
    calendar.set(Calendar.SECOND, 0);
    calendar.set(Calendar.MILLISECOND, 0);

    res = calendar.getTime();

    return res;
}

Date currentDate = getZeroTimeDate(new Date());// get current date   

这是解决这个问题最简单的方法。

如果你只想比较两个日期的月、日和年，下面的代码适用于我:

SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
sdf.format(date1).equals(sdf.format(date2));

谢谢抢劫。

对这个替代方案有什么意见吗?

SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
sdf.format(date1).equals(sdf.format(date2));