Question

我使用此代码将日期字符串转换为unix时间戳：

int year = 2012;
int month = 2; // eg. for march
int day = 31;
int hrs = 0;
int min = 18;

这应该用英语符号表示这个日期/时间31.3.2012 00:18或3/31/2012 00:18。

Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("Europe/Berlin")); // GMT+1
cal.set(year, month, day, hrs, min);
unixtime = cal.getTimeInMillis() / 1000;

unixtime的结果是：1333145929 如果我将其转换回来（cal.setTimeInMillis(1333145929 * 1000);），我得到30.3.2012 00:18

我失去了一天！

Answer 1

如何打印Calendar？

我认为你得到GMT时间，落后一小时，因此在午夜落后一天。

考虑：

public static void main(String[] args) throws Exception {
    int year = 2012;
    int month = 2; // eg. for march
    int day = 31;
    int hrs = 0;
    int min = 18;
    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("Europe/Berlin")); // GMT+1
    cal.set(year, month, day, hrs, min);
    long time = cal.getTimeInMillis();
    System.out.println(time);
    cal.setTimeInMillis(time);
    final DateFormat sdf = SimpleDateFormat.getDateTimeInstance(SimpleDateFormat.FULL, SimpleDateFormat.FULL);
    System.out.println(sdf.format(cal.getTime()));
}

输出：

1333145915825
Friday, 30 March 2012 23:18:35 o'clock BST

现在，如果我向TimeZone添加DateFormat：

final DateFormat sdf = SimpleDateFormat.getDateTimeInstance(SimpleDateFormat.FULL, SimpleDateFormat.FULL);
sdf.setTimeZone(TimeZone.getTimeZone("Europe/Berlin"));
System.out.println(sdf.format(cal.getTime()));

我明白了：

1333145887761
Saturday, 31 March 2012 00:18:07 o'clock CEST

因此，SimpleDateFormat在格式化时使用默认TimeZone，而TimeZone的{{1}} （因为您调用Calendar }}）。

Answer 2

    int year = 2012;
    int month = 2; // eg. for march
    int day = 31;
    int hrs = 0;
    int min = 18;


    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("Europe/Berlin")); // GMT+1
    cal.set(year, month, day, hrs, min);
    long unixtime = cal.getTimeInMillis();

    cal.setTimeInMillis(unixtime);

    //Lets print it!
    SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
    sdf.setTimeZone(TimeZone.getTimeZone("Europe/Berlin"));
    System.out.println(sdf.format(cal.getTime()));

对于我上面的代码打印：03/31/2012 00:18:56

如何打印日期？

Answer 3

我试过这段代码：

    int year = 2012;
    int month = 2; // eg. for march
    int day = 31;
    int hrs = 0;
    int min = 18;

    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("Europe/Berlin")); // GMT+1
    cal.set(year, month, day, hrs, min);
    long unixtime = cal.getTimeInMillis() / 1000;

    System.out.println(cal.getTime());

    System.out.println(unixtime);

    cal.setTimeInMillis(unixtime * 1000);

    System.out.println(cal.getTime());

输出是这样的：

Sat Mar 31 00:18:04 CEST 2012
1333145884
Sat Mar 31 00:18:04 CEST 2012

Answer 4

问题是你如何得到30.3.2012 00:18。日历日期字段正常，请尝试此

    Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("Europe/Berlin")); // GMT+1
    cal.set(year, month, day, hrs, min);
    long unixtime = cal.getTimeInMillis() / 1000;
    cal.setTimeInMillis(unixtime * 1000);
    System.out.println(cal.get(Calendar.DATE));

输出

Answer 5

int year = 2012;
        int month = 2; // eg. for march
        int day = 31;
        int hrs = 0;
        int min = 18;

        Calendar cal = Calendar.getInstance(TimeZone
                .getTimeZone("Europe/Berlin")); 
        cal.set(year, month, day, hrs, min);
        long unixtime = cal.getTimeInMillis() / 1000;
        cal.setTimeInMillis(unixtime * 1000);
        System.out.println(cal.getTime());

输出：

Sat Mar 31 03:48:10 IST 2012

java：日历没有得到正确的日期/时间？

5 个答案: