java - 从毫秒到天的 TimeUnit 转换对我不起作用

Question

我试图计算两个时间戳的天数之差，TimeUnit 为我返回了完全错误的结果。

这是我的代码:

long ts = 1522242239952L;
long now = 1527274162820L;
long difference = now - ts;
int ageInDays = (int) TimeUnit.MILLISECONDS.convert(difference, TimeUnit.DAYS);
int ageInDays2 = (int) (difference/(1000 * 60 * 60 * 24));
System.out.println(ageInDays);
System.out.println(ageInDays2);

输出是:

-1756844032
58

为什么 TimeUnit 计算如此不正确？

Answer 1

因为您正在反向使用 TimeUnit.convert。尝试

TimeUnit.DAYS.convert(difference, TimeUnit.MILLISECONDS);

或者只是

TimeUnit.MILLISECONDS.toDays(difference);

引用:https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/TimeUnit.html#convert(long,%20java.util.concurrent.TimeUnit)