java - 下午 4 点就下类了

Question

我试图显示两个日期之间的差异，按月、日、小时、分钟和秒分割。下面的代码似乎可以工作，只是时间总是晚 4 点。我尝试了 HOUR 和 HOUR_OF_DAY，但得到了相同的结果。

    Calendar cal = Calendar.getInstance();

    int year = cal.get(Calendar.YEAR);
    int month = cal.get(Calendar.MONTH);
    int day = cal.get(Calendar.DAY_OF_MONTH);
    int hour = cal.get(Calendar.HOUR);
    int minutes = cal.get(Calendar.MINUTE);
    int seconds = cal.get(Calendar.SECOND);


    DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

    try {
        //get the current date/time
        Date beginDate = cal.getTime();

        //fabricate a future date/time
        Date endDate = dateFormat.parse(String.valueOf(year) + "-" + String.valueOf(month)
                + "-" + String.valueOf(day+95) + " " + String.valueOf(hour+2)
                + ":" + String.valueOf(minutes +16) + ":" + String.valueOf(seconds +34));

        long millis = endDate.getTime() - beginDate.getTime();

        TextView txtMonths = (TextView) findViewById(R.id.months);
        txtMonths.setText("Months: " + (new SimpleDateFormat("M")).format(new Date(millis)));

        TextView txtDays = (TextView) findViewById(R.id.days);
        txtDays.setText("Days: " + (new SimpleDateFormat("d")).format(new Date(millis)));

        TextView txtHours = (TextView) findViewById(R.id.hours);
        txtHours.setText("Hours: " + (new SimpleDateFormat("h")).format(new Date(millis)));

        TextView txtMinutes = (TextView) findViewById(R.id.minutes);
        txtMinutes.setText("Minutes: " + (new SimpleDateFormat("m")).format(new Date(millis)));

        TextView txtSeconds = (TextView) findViewById(R.id.seconds);
        txtSeconds.setText("Seconds: " + (new SimpleDateFormat("s")).format(new Date(millis)));

    } catch (ParseException ex) {
        Log.d("ParseException", ex.toString());

    }

有人认为这是因为时区。我是 GMT +8 并且 DST = true 所以

 TimeZone timeZone = cal.getTimeZone();
 timeZone.getOffset( System.currentTimeMillis())); 

返回 7 小时而不是 4 小时。我是否缺少时区信息？

Answer 1

这是错误的我以为我有它，但我没有。

我认为这是时区，但我仍然不确定当我处于 GMT+8 且处于 DST 时它是如何得出 4 的。因此，虽然下面的代码似乎有效，但如果它在 7 或 8 点之前关闭，我会感觉更舒服。如果是这种情况，时区我会立即明白。

Java 可能很残酷。

    Calendar cal = Calendar.getInstance();
    TimeZone UTC = TimeZone.getTimeZone("UTC");
    cal.setTimeZone(UTC);

    int year = cal.get(Calendar.YEAR);
    int month = cal.get(Calendar.MONTH);
    int day = cal.get(Calendar.DAY_OF_MONTH);
    int hour = cal.get(Calendar.HOUR);
    int minutes = cal.get(Calendar.MINUTE);
    int seconds = cal.get(Calendar.SECOND);


    DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

    try {
        //get the current date/time
        Date beginDate = cal.getTime();

        //fabricate a future date/time

        endDate = dateFormat.parse(String.valueOf(year) + "-" + String.valueOf(month)
                + "-" + String.valueOf(day+95) + " " + String.valueOf(hour+2)
                + ":" + String.valueOf(minutes +1) + ":" + String.valueOf(seconds +34));
        dateFormat.setTimeZone(UTC);

        long millis = endDate.getTime() - beginDate.getTime();

        if (TimeZone.getDefault().inDaylightTime( new Date())) {
            millis += 3600000;
        }

        TextView txtMonths = (TextView) findViewById(R.id.months);
        txtMonths.setText("Months: " + (new SimpleDateFormat("M")).format(new Date(millis)));

        TextView txtDays = (TextView) findViewById(R.id.days);
        txtDays.setText("Days: " + (new SimpleDateFormat("d")).format(new Date(millis)));

        TextView txtHours = (TextView) findViewById(R.id.hours);
        txtHours.setText("Hours: " + (new SimpleDateFormat("h")).format(new Date(millis)));

        TextView txtMinutes = (TextView) findViewById(R.id.minutes);
        txtMinutes.setText("Minutes: " + (new SimpleDateFormat("m")).format(new Date(millis)));

        TextView txtSeconds = (TextView) findViewById(R.id.seconds);
        txtSeconds.setText("Seconds: " + (new SimpleDateFormat("s")).format(new Date(millis)));
    } catch (ParseException ex) {
        Log.d("ParseException", ex.toString());

    }