这是一个获取日期和时间的有用方法:

private String getDate(){
    DateFormat dfDate = new SimpleDateFormat("yyyy/MM/dd");
    String date=dfDate.format(Calendar.getInstance().getTime());
    DateFormat dfTime = new SimpleDateFormat("HH:mm");
    String time = dfTime.format(Calendar.getInstance().getTime());
    return date + " " + time;
}

你可以调用这个方法来获取当前的日期和时间值:

2017/01//09 19:23

这是一个获取日期和时间的有用方法:

private String getDate(){
    DateFormat dfDate = new SimpleDateFormat("yyyy/MM/dd");
    String date=dfDate.format(Calendar.getInstance().getTime());
    DateFormat dfTime = new SimpleDateFormat("HH:mm");
    String time = dfTime.format(Calendar.getInstance().getTime());
    return date + " " + time;
}

你可以调用这个方法来获取当前的日期和时间值:

2017/01//09 19:23

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

如果需要当前日期:

Calendar cc = Calendar.getInstance();
int year = cc.get(Calendar.YEAR);
int month = cc.get(Calendar.MONTH);
int mDay = cc.get(Calendar.DAY_OF_MONTH);
System.out.println("Date", year + ":" + month + ":" + mDay);

如果需要当前时间:

 int mHour = cc.get(Calendar.HOUR_OF_DAY);
 int mMinute = cc.get(Calendar.MINUTE);
 System.out.println("time_format" + String.format("%02d:%02d", mHour , mMinute));

下面的方法将以字符串形式返回当前日期和时间，请根据您的实际时区使用不同的时区。我用的是格林尼治时间。

public static String GetToday(){
    Date presentTime_Date = Calendar.getInstance().getTime();
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    dateFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
    return dateFormat.format(presentTime_Date);
}

你可以使用下面的代码获取当前的日期和时间:

val current_data_time= SimpleDateFormat("MMMMddyyyyHHmm", Locale.getDefault())
val currentDateandTime: String = current_data_time.format(Date())

如果你用MMMM:那么月份名称就会显示出来。“3”

如果你用MM:那么数字显示。“3”

Dd表示日，yyyy表示年

如果你只想要最后两位数字，那么yy。

如果你先改变月份和年份，然后需要左右改变MMMM、dd和yyyy，例如:12/3/2021 12:12 dd/MM/ yyyy HH: MM