GregorianCalendar - java.util

GregorianCalendar

GregorianCalendar is a concrete implementation of a Calendar that implements the normal Gregorian calendar with which you are familiar. The getInstance( ) method of Calendar will typically return a GregorianCalendar initialized with the current date and time in the default locale and time zone.

GregorianCalendar defines two fields: AD and BC. These represent the two eras defined by the Gregorian calendar.

There are also several constructors for GregorianCalendar objects. The default, GregorianCalendar( ), initializes the object with the current date and time in the default locale and time zone. Three more constructors offer increasing levels of specificity:

GregorianCalendar(int year, int month, int dayOfMonth)

GregorianCalendar(int year, int month, int dayOfMonth, int hours,

int minutes)

GregorianCalendar(int year, int month, int dayOfMonth, int hours, int minutes, int seconds)

All three versions set the day, month, and year. Here, year specifies the year. The month is specified by month, with zero indicating January. The day of the month is specified by dayOfMonth. The first version sets the time to midnight. The second version also sets the hours and the minutes. The third version adds seconds.

You can also construct a GregorianCalendar object by specifying the locale and/or time zone. The following constructors create objects initialized with the current date and time using the specified time zone and/or locale:

GregorianCalendar(Locale locale) GregorianCalendar(TimeZone timeZone) GregorianCalendar(TimeZone timeZone, Locale locale)

GregorianCalendar provides an implementation of all the abstract methods in Calendar. It also provides some additional methods. Perhaps the most interesting is isLeapYear( ), which tests if the year is a leap year. Its form is

boolean isLeapYear(int year)

This method returns true if year is a leap year and false otherwise. JDK 8 also adds the following methods: from( ) and toZonedDateTime( ), which support the new date and time API, and getCalendarType( ), which returns the calendar type as a string, which is “gregory”.

The following program demonstrates GregorianCalendar:

// Demonstrate GregorianCalendar

import java.util.*;

class GregorianCalendarDemo {

public static void main(String args[]) { String months[] = {

"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};

int year;

    //Create a Gregorian calendar initialized

    //with the current date and time in the

    //default locale and timezone.

GregorianCalendar gcalendar = new GregorianCalendar();

// Display current time and date information.

 System.out.print("Date: ");

System.out.print(months[gcalendar.get(Calendar.MONTH)]);

System.out.print(" " + gcalendar.get(Calendar.DATE) + " "); System.out.println(year = gcalendar.get(Calendar.YEAR));

System.out.print("Time: ");

System.out.print(gcalendar.get(Calendar.HOUR) + ":");

System.out.print(gcalendar.get(Calendar.MINUTE) + ":");

System.out.println(gcalendar.get(Calendar.SECOND));

// Test if the current year is a leap year

if(gcalendar.isLeapYear(year)) {

System.out.println("The current year is a leap year");

}

else {

System.out.println("The current year is not a leap year");

}

}

}

Sample output is shown here:

Date: Jan 1 2014 Time: 1:45:5

The current year is not a leap year