Getting Started with Java--date action class

Getting Started with Java--date action class Date class

　　

is a simpler operation class, using the construction method of the Java.util.Data class and outputting it to get a full Date. The construction method is: public Data ();

Java.util package needs to be imported

Package Sep26;import Java.util.date;public class DataDemo01 {public static void main (string[] Args) {date date=new Date (); System.out.println ("the Current date is:" +date);}}

The current date is: Mon SEP 2016 10:57:57 CST

Use the Calendar class to get Rich-format dates

Calendar class

The Calendar class is an abstract class that can rely on the polymorphism of the object to instantiate the parent class through subclasses, and the subclass of the Calendar class is the GregorianCalendar class.

Property:

Serial number	Constant	Type	Describe
1	public static final int year	Int	Acquired year
2	public static final int MONTH	Int	Get the Month
3	public static final int Day_of_month	Int	Acquisition Date
4	public static final int Hour_of_day	Int	Get an hour, 24-hour system
5	public static final int MINUTE	Int	Get points
6	public static final int SECOND	Int	Get seconds
7	public static final int Milliseond	Int	Get milliseconds

Method:

ordinal	method	type	description
1	public static Calendar getinstance ()	normal	instantiating objects by default time zone
2	public Beelean after (obeject When)	Normal	to determine whether a date is before a date
3	public Beelean before (obeject when)	normal	determine if a date is after a date
4	public int get (int field)	normal	Returns the value of a given calendar field

Package Sep26;import Java.util.calendar;import Java.util.gregoriancalendar;public class DateDemo02 {public static void Main (string[] Args) {Calendar calendar=null;calendar=new GregorianCalendar (); System.out.println ("year:" +calendar.get (calendar.year)); System.out.println ("month:" +calendar.get (calendar.month) +1);//month is calculated from 0, so +1system.out.println ("day:" +calendar.get ( calendar.day_of_month)); System.out.println ("time:" +calendar.get (calendar.hour_of_day)); System.out.println ("points:" +calendar.get (calendar.minute)); System.out.println ("seconds:" +calendar.get (calendar.second)); System.out.println ("ms:" +calendar.get (calendar.millisecond));}}

Year: 2016 Months: 81 days: 26 o'clock: 11 minutes: 20 seconds: 3 ms: 384

The time it takes to get the system in this way is more complicated, so Java provides other convenient system time classes to show the customary system time

DateFormat class

The format class is a class that is used to format data, and the DateFormat class is a subclass of It: the DateFormat class is also an abstract class, but the abstract class provides a static method that allows you to get an instance of this class Directly.

Package Sep26;import Java.util.*;import java.text.*;p ublic class DateDemo03 {public static void main (string[] Args) {Date Format df1=null;dateformat df2=null;df1=dateformat.getdateinstance (dateformat.year_field,new Locale ("zh", "CN")); Df2=dateformat.getdatetimeinstance (dateformat.year_field,dateformat.era_field,new Locale ("zh", "CN")); System.out.println ("date:" +df1.format (new Date ())); System.out.println ("date:" +df2.format (new Date ()));}}

date:2016 September 26 date:2016 September 26 11:37 A.M. 59 sec CST

SimpleDateFormat class (most commonly Used)

First define a full date conversion template, which is marked by a specific date in the Template:

Serial number	Mark	Describe
1	yyyy	Years
2	Mm	Month
3	Dd	Day
4	HH	Hours
5	Mm	Minutes
6	Ss	Seconds
7	Ss	Milliseconds

Getting Started with Java--date action class