Java Calendar类

本文概述

• Java Calendar类声明
• 日历方法清单
• Java Calendar类示例
• Java Calendar类示例：get()
• Java Calendar类示例：getInstance()
• Java Calendar类示例：getMaximum()
• Java Calendar类示例：getMinimum()

Java Calendar类是一个抽象类, 它提供在特定时间点和一组日历字段（例如MONTH, YEAR, HOUR等）之间转换日期的方法。它继承了Object类并实现Comparable接口。

Java Calendar类声明

让我们看看java.util.Calendar类的声明。

public abstract class Calendar extends Object 
implements Serializable, Cloneable, Comparable<Calendar>

日历方法清单

Java Calendar类示例

import java.util.Calendar;
public class CalendarExample1 {
   public static void main(String[] args) {
   Calendar calendar = Calendar.getInstance();
   System.out.println("The current date is : " + calendar.getTime());
   calendar.add(Calendar.DATE, -15);
   System.out.println("15 days ago: " + calendar.getTime());
   calendar.add(Calendar.MONTH, 4);
   System.out.println("4 months later: " + calendar.getTime());
   calendar.add(Calendar.YEAR, 2);
   System.out.println("2 years later: " + calendar.getTime());
   }
}

立即测试

输出：

The current date is : Thu Jan 19 18:47:02 IST 2017
15 days ago: Wed Jan 04 18:47:02 IST 2017
4 months later: Thu May 04 18:47:02 IST 2017
2 years later: Sat May 04 18:47:02 IST 2019

Java Calendar类示例：get()

import java.util.*;
public class CalendarExample2{
  public static void main(String[] args) {
   Calendar calendar = Calendar.getInstance();
   System.out.println("At present Calendar's Year: " + calendar.get(Calendar.YEAR));
   System.out.println("At present Calendar's Day: " + calendar.get(Calendar.DATE));
   }
}

立即测试

输出：

At present Calendar's Year: 2017
At present Calendar's Day: 20

Java Calendar类示例：getInstance()

import java.util.*;
public class CalendarExample3{
   public static void main(String[] args) {
   Calendar calendar = Calendar.getInstance();
   System.out.print("At present Date And Time Is: " + calendar.getTime());
   }
}

立即测试

输出：

At present Date And Time Is: Fri Jan 20 14:26:19 IST 2017

Java Calendar类示例：getMaximum()

import java.util.*;
public class CalendarExample4 {
   public static void main(String[] args) {
   Calendar calendar = Calendar.getInstance();
   int maximum = calendar.getMaximum(Calendar.DAY_OF_WEEK);
   System.out.println("Maximum number of days in week: " + maximum);
   maximum = calendar.getMaximum(Calendar.WEEK_OF_YEAR);
   System.out.println("Maximum number of weeks in year: " + maximum);
   }
}

立即测试

输出：

Maximum number of days in week: 7
Maximum number of weeks in year: 53

Java Calendar类示例：getMinimum()

import java.util.*;
public class CalendarExample5 {
   public static void main(String[] args) {
   Calendar cal = Calendar.getInstance();
   int maximum = cal.getMinimum(Calendar.DAY_OF_WEEK);
   System.out.println("Minimum number of days in week: " + maximum);
   maximum = cal.getMinimum(Calendar.WEEK_OF_YEAR);
   System.out.println("Minimum number of weeks in year: " + maximum);
   }
}

立即测试

输出：

Minimum number of days in week: 1
Minimum number of weeks in year: 1