Java gets the current date and time

Original address: http://www.blogjava.net/parable-myth/archive/2013/01/17/394364.html

There are three ways to do this:

Method one: With the Java.util.Date class to achieve, and combined with the Java.text.DateFormat class to achieve the format of time, see the following code:

Import java.util.*;
Import java.text.*;
//The following default time and date display is in Chinese language mode
//General language default Chinese is available, the format of the time date is medium style, such as: 2008-6-16 20:54:53
// The dates and times shown below are based on the date class, and can be implemented using the Calendar class Testdate2.java
public class TestDate {
public static void main ( String[] (args) {
Date now = new Date ();
Calendar cal = Calendar.getinstance ();

DateFormat d1 = dateformat.getdateinstance ();//default style (medium style, for example: 2008-6-16 20:54:53) in default language (Chinese)
String STR1 = D1.format (now);
DateFormat d2 = Dateformat.getdatetimeinstance ();
String str2 = D2.format (now);
DateFormat d3 = Dateformat.gettimeinstance ();
String STR3 = D3.format (now);
DateFormat d4 = dateformat.getinstance ();//use short style to display the date and time
String STR4 = D4.format (now);

DateFormat d5 = Dateformat.getdatetimeinstance (dateformat.full,dateformat.full); Display date, week, time (accurate to seconds)
String STR5 = D5.format (now);
DateFormat d6 = dateformat.getdatetimeinstance (Dateformat.long,dateformat.long); Displays the date. Time (accurate to seconds)
String STR6 = D6.format (now);
DateFormat D7 = dateformat.getdatetimeinstance (Dateformat.short,dateformat.short); Display date, time (accurate to minute)
String STR7 = D7.format (now);
DateFormat D8 = Dateformat.getdatetimeinstance (Dateformat.medium,dateformat.medium); Display date, time (accurate to minute)
String str8 = D8.format (now);//compared with short style, this method is the most useful

System.out.println ("Show Time in Date:" + now);//The result shown by this method is the same as Calendar.getinstance (). GetTime ().


SYSTEM.OUT.PRINTLN ("formatted with Dateformat.getdateinstance () after the time:" + str1);
SYSTEM.OUT.PRINTLN ("formatted with Dateformat.getdatetimeinstance () after the time:" + str2);
SYSTEM.OUT.PRINTLN ("formatted with Dateformat.gettimeinstance () after the time:" + STR3);
SYSTEM.OUT.PRINTLN ("formatted with Dateformat.getinstance () after the time:" + STR4);

SYSTEM.OUT.PRINTLN ("Formatted time with Dateformat.getdatetimeinstance (dateformat.full,dateformat.full):" + STR5);
SYSTEM.OUT.PRINTLN ("Formatted time with Dateformat.getdatetimeinstance (Dateformat.long,dateformat.long):" + STR6);
SYSTEM.OUT.PRINTLN ("Formatted time with Dateformat.getdatetimeinstance (Dateformat.short,dateformat.short):" + STR7);
SYSTEM.OUT.PRINTLN ("Formatted time with Dateformat.getdatetimeinstance (Dateformat.medium,dateformat.medium):" + str8);
}

}

Operation Result:

Display time in Date: Mon June 20:54:53 CST 2008
Format time with Dateformat.getdateinstance (): 2008-6-16
Format time with Dateformat.getdatetimeinstance (): 2008-6-16 20:54:53
After formatting the time with Dateformat.gettimeinstance (): 20:54:53
After formatting the time with Dateformat.getinstance (): 08-6-16 8:54
Format time with Dateformat.getdatetimeinstance (dateformat.full,dateformat.full): June 16, 2008 Monday 08:54 P.M. 53 sec CST
Format time with Dateformat.getdatetimeinstance (Dateformat.long,dateformat.long): June 16, 2008 08:54 P.M. 53 seconds
After formatting the time with Dateformat.getdatetimeinstance (dateformat.short,dateformat.short): 08-6-16 8:54
Formatted time with Dateformat.getdatetimeinstance (dateformat.medium,dateformat.medium): 2008-6-16 20:54:53

Method Two: Use the Java.util.Calendar class to achieve, see below:

Import java.util.*;
Import java.text.*;
The following is the use of the Calendar class to implement date time, and the date class is relatively simple

public class TestDate2 {
public static void Main (string[] args) {

Calendar CA = Calendar.getinstance ();
int year = Ca.get (calendar.year);//Get Years
int Month=ca.get (calendar.month);//Get month
int Day=ca.get (calendar.date);//Acquisition Day
int Minute=ca.get (calendar.minute);//min
int Hour=ca.get (calendar.hour);//hour
int Second=ca.get (calendar.second);//sec
int weekofyear = Ca.get (Calendar.day_of_week);


System.out.println ("with Calendar.getinstance (). GetTime () mode display time:" + ca.gettime ());
System.out.println ("Get Date with calendar:" + year + "years" + month + "Month" + Day + "Days");

SYSTEM.OUT.PRINTLN ("Use calendar to get time is:" + hour + "when" + Minute + "min" + second + "seconds");
System.out.println (weekofyear);//show today is the day of the week (I do this example is exactly Tuesday, so the results show 2, if you run again 6 weeks, then show 6)

}

}

Display time by Calendar.getinstance (). GetTime (): Mon June 21:54:21 CST 2008
Use calendar to get the date: May 16, 2008 Note: This is May, and actually June, because the calendar month is 0~11 corresponds to 1-12 months.
Use Calendar to get time is: 9:54 21 seconds Note: Here is a 12-hour system, to obtain 24-hour system, you need to use inthour=ca.get (calendar.hour_of_day);//hour

Method Three:

SimpleDateFormat 24-hour system time display

Letters	date or time element	represents	Example
G	Era Marker	Text	AD
y	Years	Year	1996;96
M	Month of the Year	Month	July; Jul;07
w	Number of weeks in the year	Number	27
W	Number of weeks in the month	Number	2
D	Number of days in the year	Number	189
d	Number of days in month	Number	10
F	Week of the Month	Number	2
E	Days of the Week	Text	Tuesday;Tue
a	AM/PM Mark	Text	PM
H	Number of hours in the day (0-23)	Number	0
k	Number of hours in the day (1-24)	Number	24
K	Number of hours in am/pm (0-11)	Number	0
h	Number of hours in am/pm (1-12)	Number	12
m	Number of minutes in hours	Number	30
s	Number of seconds in minutes	Number	55
S	Number of milliseconds	Number	978
z	Time	General Time Zone	Pacific Standard Time; PST;GMT-08:00
Z	Time	RFC 822 Time Zone	-0800

It has the advantage of supporting two-bit months, two-bit dates. Prefixed with 0. Date date = new Date (); SimpleDateFormat DateFormat = new SimpleDateFormat ("Yyyy-mm-dd hh:mm"); String Sdatesuffix = Dateformat.format (date); System.out.println ("[+]sdatesuffix:" +sdatesuffix);

Java gets the current date and time