Java Date class and SimpleDateFormat dates class format

~date represents a specific time, accurate to milliseconds
~ Construction Method:
Public date ()//time when the date object was constructed and initialized to the current system
Public date (long date)//1970-1-1 0:0:0 the number of milliseconds to the specified time

~ Common methods:
Public long GetTime ()//1970-1-1 0:0:0 to the current number of milliseconds
Public long settime ()//Set Date Time
public boolean befor (date time)//test whether this date is before the specified date
public Boolean after (date time)//test whether this date is after the specified date
public int CompareTo (date anotherdate)//assumes that the current date is before the date parameter, returns <0; the current date after the date parameter, and returns >0
public string toString ()//Convert date format to string format output

~dateformat is a date/time formatted abstract class that formats and parses dates or times in a language-neutral way
~ Date/Time formatting subclasses (such as SimpleDateFormat) allow formatting (that is, date-and text), parsing (text--date)
~ Construction Method:
Public Simlpedateformat ()
Public SimpleDateFormat (String pattern)
~ Common methods:
Public final string format (date date)//date to String
Public Date Parse (string source)//string converted to date

ImportJava.text.DateFormat;ImportJava.text.SimpleDateFormat;Importjava.util.Date;ImportJava.util.Locale; Public classDatedemo { Public Static voidMain (string[] args) {//TODO auto-generated Method StubDate Date =NewDate ();        SYSTEM.OUT.PRINTLN (date); System.out.println (Date.gettime ());//returns the number of milliseconds from 1970.1.1 to the presentDate.settime (1519807159999L);//Modification TimeSystem.out.println (date); DateFormat DF1=NULL;//DateFormat is not instantiated for abstract classesDateFormat DF2 =NULL;//Ibid .DF1 = Dateformat.getdateinstance ();//implement subclass object, get dateDF2 = Dateformat.getdatetimeinstance ();//Get date + timeSystem.out.println ("Date:" +df1.format (date));//converts a string to a date format, fixedSystem.out.println ("DateTime:" +df2.format (date));//Convert a string to date + time format, format fixedDateFormat df3=NULL; DF3= Dateformat.getdateinstance (Dateformat.full,NewLocale ("zh", "CN"));//format to Chinese date mode. There are four formats of Short,medium,long,fullSystem.out.println ("Date:" +df3.format (date));//Convert a string to date + time format, format fixedDateFormat DF4 =NULL; DF4= Dateformat.getdatetimeinstance (Dateformat.full,dateformat.full,NewLocale ("zh", "CN")); System.out.println ("DateTime:" +df4.format (date));//Convert a string to date + time format, format fixed//SimpleDateFormat Subclasses can customize the output format for more flexibilityString strdate = "2018-2-29 18:30:00.123"; Date D=NULL; SimpleDateFormat SDF1=NewSimpleDateFormat ("Yyyy-mm-dd HH:mm:ss. SSS "); SimpleDateFormat SDF2=NewSimpleDateFormat ("yyyy mm month DD Day Hh-mm-ss.sss"); Try{//If there is a format to write an exception, throw the exceptionD =Sdf1.parse (strdate); }Catch(Exception e) {} System.out.println (d); String Str= Sdf2.format (d);//output the date in the specified formatSystem.out.println (str); }}

Java Date class and SimpleDateFormat date class format