Java Notes------Date API

Some of the APIs involved:

Calendar Calendar = Calendar. getinstance ();

Calendar. getTime ();
Calendar. settime (date);
Calendar. Set (calendar.year,2000);
Calendar. Get (calendar.date);
Calendar. Add (Calendar.day_of_year, 10);
Calendar. Getactualmaximum (Calendar.day_of_month);
Calendar1. After (CALENDAR2);
Calendar. Gettimeinmillis ();

SimpleDateFormat SDF = new SimpleDateFormat ();

Sdf. parse ();
Sdf. format ();

SimpleDateFormat SDF = new SimpleDateFormat ("yyyy-mm-dd HH:mm:ss E");

String strtime = sdf. format (date);

Date = SDF. Parse (Strtime);

For example, the following code is shown:

1  Packagetest;2 3 Importjava.text.ParseException;4 ImportJava.text.SimpleDateFormat;5 ImportJava.util.Calendar;6 Importjava.util.Date;7 8  Public classDatedemo {9 Ten      Public Static voidMain (string[] args)throwsParseException { OneDate Date =NewDate (); A          -         //current time millisecond value, long type -         LongNumtime =date.gettime (); the System.out.println (numtime); -          -         //constructs SimpleDateFormat objects in "Yyyy-mm-dd HH:mm:ss E" format -SimpleDateFormat SDF =NewSimpleDateFormat ("Yyyy-mm-dd HH:mm:ss E"); +          -         //generates a string time in SDF format (specified in the constructor method) based on the date type Object +String Strtime =Sdf.format (date); A System.out.println (strtime); at          -         //generates a date type object from the string strtime in the format in SDF (specified in the constructor method) -Date =Sdf.parse (strtime); - System.out.println (date); -          -         //Calendar is an abstract class and cannot be generated directly from new inCalendar Calendar =calendar.getinstance (); -Calendar calendar2 =Calendar; toSYSTEM.OUT.PRINTLN (Calendar);//This output is straightforward to read, java.util.gregoriancalendar[time=1504450592066,arefieldsset=true,areallfieldsset=true,lenient= True,zone=sun.util.calendar.zoneinfo[id= "gmt+08:00", offset=28800000,dstsavings=0,usedaylight=false,transitions =0,lastrule=null],firstdayofweek=1,minimaldaysinfirstweek=1,era=1,year=2017,month=8,week_of_year=36,week_of_ Month=2,day_of_month=3,day_of_year=246,day_of_week=1,day_of_week_in_month=1,am_pm=1,hour=10,hour_of_day=22, Minute=56,second=32,millisecond=66,zone_offset=28800000,dst_offset=0] +          -         //Get Date Object theDate =calendar.gettime (); *          $         //set time in date to calendarPanax Notoginseng calendar.settime (date); -          the         //Get + Calendar.get (calendar.year); A          the         //Set +Calendar.set (calendar.month, 0); -          $         //Increase $Calendar.add (Calendar.day_of_year, 10); -          -         //Specifies the maximum value that a calendar field may have. The maximum number of days in the current month in this sentence.  the Calendar.getactualmaximum (calendar.day_of_month); -         Wuyi          the          -         //Boolean type that determines whether the calendar1 time is after Calendar2 Wu Calendar.after (CALENDAR2); -          About         //gets the millisecond value that returns a long type $ Calendar.gettimeinmillis (); -          -          -     } A  +}

Java Notes------Date API