如何在Android应用程序中获取当前时间和日期?
当前回答
你可以(但不再应该-见下文!)使用android.text.format.Time:
Time now = new Time();
now.setToNow();
从上面的参考链接:
Time类是一个更快的替代品 为java.util.Calendar和 java.util.GregorianCalendar类。 Time类的实例 表示指定的时间点 精准度第二。
注1: 我写这个答案已经有好几年了, 它是关于一个旧的,android专用的,现在已被弃用的类。 谷歌现在这样说 “他的类有一些问题,建议使用公历代替”。
注2:尽管Time类有一个toMillis(ignoreDaylightSavings)方法,但这只是为了方便传递给以毫秒为单位的方法。时间值仅精确到一秒;毫秒部分总是000。如果在循环中,你会这样做
Time time = new Time(); time.setToNow();
Log.d("TIME TEST", Long.toString(time.toMillis(false)));
... do something that takes more than one millisecond, but less than one second ...
结果序列将重复相同的值,例如1410543204000,直到下一秒开始,此时1410543205000将开始重复。
其他回答
SimpleDateFormat databaseDateTimeFormate = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
SimpleDateFormat databaseDateFormate = new SimpleDateFormat("yyyy-MM-dd");
SimpleDateFormat sdf1 = new SimpleDateFormat("dd.MM.yy");
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy.MM.dd G 'at' hh:mm:ss z");
SimpleDateFormat sdf3 = new SimpleDateFormat("EEE, MMM d, ''yy");
SimpleDateFormat sdf4 = new SimpleDateFormat("h:mm a");
SimpleDateFormat sdf5 = new SimpleDateFormat("h:mm");
SimpleDateFormat sdf6 = new SimpleDateFormat("H:mm:ss:SSS");
SimpleDateFormat sdf7 = new SimpleDateFormat("K:mm a,z");
SimpleDateFormat sdf8 = new SimpleDateFormat("yyyy.MMMMM.dd GGG hh:mm aaa");
String currentDateandTime = databaseDateTimeFormate.format(new Date()); //2009-06-30 08:29:36
String currentDateandTime = databaseDateFormate.format(new Date()); //2009-06-30
String currentDateandTime = sdf1.format(new Date()); //30.06.09
String currentDateandTime = sdf2.format(new Date()); //2009.06.30 AD at 08:29:36 PDT
String currentDateandTime = sdf3.format(new Date()); //Tue, Jun 30, '09
String currentDateandTime = sdf4.format(new Date()); //8:29 PM
String currentDateandTime = sdf5.format(new Date()); //8:29
String currentDateandTime = sdf6.format(new Date()); //8:28:36:249
String currentDateandTime = sdf7.format(new Date()); //8:29 AM,PDT
String currentDateandTime = sdf8.format(new Date()); //2009.June.30 AD 08:29 AM
日期格式
G Era designator (before christ, after christ)
y Year (e.g. 12 or 2012). Use either yy or yyyy.
M Month in year. Number of M's determine length of format (e.g. MM, MMM or MMMMM)
d Day in month. Number of d's determine length of format (e.g. d or dd)
h Hour of day, 1-12 (AM / PM) (normally hh)
H Hour of day, 0-23 (normally HH)
m Minute in hour, 0-59 (normally mm)
s Second in minute, 0-59 (normally ss)
S Millisecond in second, 0-999 (normally SSS)
E Day in week (e.g Monday, Tuesday etc.)
D Day in year (1-366)
F Day of week in month (e.g. 1st Thursday of December)
w Week in year (1-53)
W Week in month (0-5)
a AM / PM marker
k Hour in day (1-24, unlike HH's 0-23)
K Hour in day, AM / PM (0-11)
z Time Zone
String DataString = DateFormat.getDateInstance(DateFormat.SHORT).format(Calendar.getInstance().getTime());
获取单元本地化格式的短日期格式字符串。
我不明白为什么这么多答案使用硬编码的日期和时间格式,而OS/Java提供了正确的日期和时间本地化。总是使用设备的格式不是比使用程序员的格式更好吗?
它还提供了本地化格式的日期读取:
DateFormat format = DateFormat.getDateInstance(DateFormat.SHORT);
Date date = null;
try {
date = format.parse(DateString);
}
catch(ParseException e) {
}
然后由用户来设置显示日期和时间的格式,而不是你。不论语言等,同一种语言在不同的国家有不同的格式。
Date todayDate = new Date();
todayDate.getDay();
todayDate.getHours();
todayDate.getMinutes();
todayDate.getMonth();
todayDate.getTime();
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.
一件容易的事。您可以剖析时间,以获得当前时间的单独值,如下所示:
Calendar cal = Calendar.getInstance();
int millisecond = cal.get(Calendar.MILLISECOND);
int second = cal.get(Calendar.SECOND);
int minute = cal.get(Calendar.MINUTE);
// 12-hour format
int hour = cal.get(Calendar.HOUR);
// 24-hour format
int hourofday = cal.get(Calendar.HOUR_OF_DAY);
日期也一样,如下所示:
Calendar cal = Calendar.getInstance();
int dayofyear = cal.get(Calendar.DAY_OF_YEAR);
int year = cal.get(Calendar.YEAR);
int dayofweek = cal.get(Calendar.DAY_OF_WEEK);
int dayofmonth = cal.get(Calendar.DAY_OF_MONTH);
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