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 |
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Getting Started with Java--date action class