//currentTimeMillis is System.currentTimeMillis()

    long totalSeconds = currentTimeMillis / 1000;
    int currentSecond = (int)totalSeconds % 60;

    long totalMinutes = totalSeconds / 60;
    int currentMinute = (int)totalMinutes % 60;

    long totalHours = totalMinutes / 60;
    int currentHour = (int)totalHours % 12;

    TextView tvTime = findViewById(R.id.tvTime);
    tvTime.setText((currentHour + OR - TIME YOU ARE FROM GMT) + ":" + currentMinute + ":" + currentSecond);

你可以用:

import java.util.Calendar;
import java.util.Date;

Date currentTime = Calendar.getInstance().getTime();

Calendar中有许多常量可以满足您的所有需要。

检查Calendar类文档。

实际上，使用time . getcurrenttimezone()在设备上设置当前时区更安全，否则您将获得UTC的当前时间。

Time today = new Time(Time.getCurrentTimezone());
today.setToNow();

然后，你可以得到你想要的所有日期字段，例如:

textViewDay.setText(today.monthDay + "");             // Day of the month (1-31)
textViewMonth.setText(today.month + "");              // Month (0-11)
textViewYear.setText(today.year + "");                // Year 
textViewTime.setText(today.format("%k:%M:%S"));  // Current time

详情请参阅android.text.format.Time类。

更新

正如许多人指出的那样，谷歌说这个类有一些问题，不应该再使用了:

This class has a number of issues and it is recommended that GregorianCalendar is used instead. Known issues: For historical reasons when performing time calculations all arithmetic currently takes place using 32-bit integers. This limits the reliable time range representable from 1902 until 2037.See the wikipedia article on the Year 2038 problem for details. Do not rely on this behavior; it may change in the future. Calling switchTimezone(String) on a date that cannot exist, such as a wall time that was skipped due to a DST transition, will result in a date in 1969 (i.e. -1, or 1 second before 1st Jan 1970 UTC). Much of the formatting / parsing assumes ASCII text and is therefore not suitable for use with non-ASCII scripts.

试着用简单的方法获取当前的日期和时间:

SimpleDateFormat sdf = new SimpleDateFormat("yyyy.MM.dd G 'at' HH:mm:ss z");
String currentDateandTime = sdf.format(new Date());

你可以通过这个函数得到你的当地时间和GMT时间

public String getCurrentDate() {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy MMM dd hh:mm a zzz");
    Date date = new Date();
    sdf.setTimeZone(TimeZone.getTimeZone("GMT+6:00"));
    return sdf.format(date);
}

对于后缀为“AM”或“PM”的12小时时钟:

DateFormat df = new SimpleDateFormat("KK:mm:ss a, dd/MM/yyyy", Locale.getDefault());
String currentDateAndTime = df.format(new Date());

对于带有“AM”或“PM”后缀的24小时时钟:

 DateFormat df = new SimpleDateFormat("HH:mm:ss a, dd/MM/yyyy", Locale.getDefault());
 String currentDateAndTime = df.format(new Date());

要删除后缀，只需删除以时间格式书写的“a”。