Date and Time in Java (Date,calendar)

1. Calendar is an abstract class, static method GetInstance () can get an instance of it

Calendar CA = calendar.getinstance ();
Ca.set (2015, 10,20);//through Set You can set year, month, date, hour, minute, second, note that the month is 0-11 from 0 (default is the current time of the system);

System.out.println (Ca.get (calendar.year));//Through Get (CALENDAR.XXX) can get the corresponding month day seconds;

The following methods can be used to obtain the current day of this XX:

Get (Calendar.day_of_month) get the day of the month

Get (Calendar.day_of_week) get the day of the week

Get (Calendar.day_of_year) get the day of the year

Gettimemillis () Gets the millisecond representation of the current time

2. Conversion of calendar and date

(1) Date date = Cal.gettime ();

(2) Date date = new Date (); Cal.settime (date) ;

3. Format output Date Time

Date date = new Date ();

SimpleDateFormat sdf = new SimpleDateFormat ("Yy-mm-dd hh:mm:ss");//month mm caps are differentiated from minute mm;
System.out.println (Sdf.format (date));//15-07-31 07:51:25

4. Date

Now, let's look at adding hours to a Date object. All date operations on date need to be completed by adding milliseconds to date. For example, if we want to add 6 hours, then we need to convert 6 hours into milliseconds. 6 hours = 6 * 60 * 60 * 1000 Ms. Take a look at the example below.  

Date date = new Date (),//increase time by 6 Hrsdate.settime (Date.gettime () + 6 * 60 * 60 * 1000); SYSTEM.OUT.PRINTLN (date);//decrease time by 6 hrsdate = new Date ();d ate.settime (Date.gettime ()-6 * 60 * 60 * 1000); SYSTEM.OUT.PRINTLN (date);

The formatted date needs to be done using the DateFormat class. Let's look at a few examples.

Formatting DatesSystem.out.println (dateformat.getinstance (). Format (        date);//10/16/12 5:18 AM

The formatted date with the locale is as follows:

System.out.println (Dateformat.getdateinstance (        dateformat.full, New Locale ("It", "it"))        . Format (date);// marted“ Ottobre 2012system.out.println (dateformat.getdateinstance (        dateformat.full, Locale.italian)        . Format ( Date));//marted“ Ottobre 2012//this uses default locale USSystem.out.println (dateformat.getdateinstance (Dateformat.full        ). Format (date);//tuesday, October, 2012system.out.println (Dateformat.getdateinstance ()        . Format (date));//oct 2012system.out.println (Dateformat.getdateinstance (        dateformat.short). Format (date));//10/16/ 12system.out.println (Dateformat.getdateinstance (        dateformat.medium). Format (date));//oct 16, 2012system.out.println (Dateformat.getdateinstance (        dateformat.long). Format (date));//october 16, 2012

Date and Time in Java (Date,calendar)