java - 在java中查找天数差异

Question

在咨询了几个论坛之后，我最终使用下面的代码来查找天差。但是，我发现逻辑有问题(可能是我的疏忽？)。我看到 11 到 14 和 11 到 15 之间的天数差异是相同的。怎么可能？

Date createdDate = new Date((2013 + 1900), (1 + 1), 11);
Date expirationDate = new Date((2013 + 1900), (1 + 1), 11);
for (int i = 11; i < 20; i++) {
    expirationDate.setDate(i);

    System.out.println("11 to " + i + " = "
            + (int) (expirationDate.getTime() - createdDate.getTime())
            / (1000 * 60 * 60 * 24));
}

输出是:

11 to 11 = 0
11 to 12 = 1
11 to 13 = 2
11 to 14 = 3
11 to 15 = 3
11 to 16 = 4
11 to 17 = 5
11 to 18 = 6
11 to 19 = 7

Answer 1

使用Joda Time的 Days#daysBetween() .没有更好的方法。

DateMidnight createdDate = new DateMidnight(2013, 2, 11);

for (int i = 11; i < 20; i++) {

    DateMidnight expirationDate = new DateMidnight(2013, 2, i);
    int dayDifference = Days.daysBetween(createdDate, expirationDate);

    System.out.println("11 to " + i + " = " + dayDifference);
}