java - Joda的DateTime与java.util.Calendar不一致

Question

我使用下面的代码来检查joda的DateTime和java.util.Calendar之间的一致性。这个结果是正确的，但是如果我将 2000 年更改为 1900 年，那么我将得到 2 个不同的结果。这是一个错误还是其他原因导致的？

Calendar c = Calendar.getInstance();
c.set(1900,0,1,0,0,0);  // Calendar's month is 0 based
c.set(Calendar.MILLISECOND, 0);
System.out.println(c.getTimeInMillis() / 1000);
DateTime dt = new DateTime(1900,1,1,0,0,0);   // joda's month is 1 based
System.out.println(dt.getMillis() / 1000);

这是输出

-2209017600
-2209017943

Answer 1

还有别的事:)

import org.joda.time.DateTime; 
import java.util.Calendar;

public class DateTester {

    public static void main(String[] args) {
        Calendar c = Calendar.getInstance();
        c.set(1900,0,1,0,0,0);
        c.set(Calendar.MILLISECOND, 0);
        System.out.println(c.getTimeInMillis()/1000);
        DateTime dt = new DateTime(1900,1,1,0,0,0);
        System.out.println(dt.getMillis()/1000);
    }
}

结果:

-2208992400
-2208992400

Process finished with exit code 0

这与 UTC 和您的时区之间的偏移有关。我的时区是 1893

import org.joda.time.DateTime;  
import java.util.Calendar;

public class DateTester {
    public static void main(String[] args) {
        Calendar c = Calendar.getInstance();
        int i = 1900;
        boolean found = false;
        while (!found) {
            c.set(i,0,1,0,0,0);
            c.set(Calendar.MILLISECOND, 0);
            DateTime dt = new DateTime(i,1,1,0,0,0);
            found = !(c.getTimeInMillis() == dt.getMillis());
            if (found) {
                System.out.println("year: " + i);
                System.out.println(c.getTimeInMillis());
                System.out.println(dt.getMillis());
            }
            i--;
        }
    }
}

结果:

year: 1893
-2429830800000
-2429830408000

UTC 与设定时区之间的偏移量可以在时区数据库中查看