java.util.Calendar clone()方法

java.util.Calendar.clone() 方法是对象类的方法，而Object类是所有Java类的超类。也可以为日历类的对象调用clone() 方法。克隆方法返回对象的副本。

1 语法

public Object clone()  

2 参数

无

3 返回值

此方法返回此对象的副本。

4 示例1 

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.util.Calendar clone()方法的例子
 */
import java.util.Calendar;  
public class CalendarCloneExample1 {  
public static void main(String[] args) {  
      // create new calendar object.  
     Calendar cal = (Calendar)  Calendar.getInstance();  
      // print date for default value  
      System.out.println("Actual Calendar Object : " + cal.getTime());  
      // create a clone of first calendar object  
     Calendar cal2 = (Calendar) cal.clone();  
      // display the copy  
      System.out.println("Cloned calendar object : " + cal2.getTime());  
   }  
}  

输出结果为：

Actual Calendar Object : Mon Jul 30 09:28:59 PDT 2018
Cloned calendar object : Mon Jul 30 09:28:59 PDT 2018

5 示例2

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.util.Calendar clone()方法的例子
 */
import java.util.Calendar;  
public class CalendarCloneExample2 {  
public static void main(String[] args) {  
      // create a new calendar object  
     Calendar cal = (Calendar) Calendar.getInstance();  
      // print the current date and time  
      System.out.println("" + cal.getTime());  
// add 9 years to the YEAR feild  
      cal.add((Calendar.YEAR), 9);  
// create clone of first calendar object        
Calendar cal2 = (Calendar) cal.clone();  
      // display the copy  
      System.out.println("Cloned calendar object : " + cal2.getTime());  
}  
}  

输出结果为：

Mon Jul 30 09:39:08 PDT 2018
Cloned calendar object: Fri Jul 30 09:39:08 PDT 2027

6 示例3

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.util.Calendar clone()方法的例子
 */
import java.util.Calendar;  
public class CalendarCloneExample3 {  
    public static void main(String[] args) {  
    // create a new calendar  
       Calendar cal = (Calendar) Calendar.getInstance();  
      // print the current date and time  
      System.out.println("" + cal.getTime());  
// add 4 months to the MONTH feild  
      cal.add((Calendar.MONTH), 4);  
      //clone the first calendar object  
Calendar cal2 = (Calendar) cal.clone();  
      // display the copy  
      System.out.println("Cloned calendar object : " + cal2.getTime());        
}  
}

输出结果为：

Mon Jul 30 09:42:52 PDT 2018
Cloned calendar object : Fri Nov 30 09:42:52 PST 2018

7 示例4

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.util.Calendar clone()方法的例子
 */
import java.util.Calendar;  
public class CalendarCloneExample4 {  
public static void main(String[] args) {  
      // create a new calendar  
     Calendar cal = (Calendar) Calendar.getInstance();  
      // print the current date and time  
      System.out.println("" + cal.getTime());  
      cal.add((Calendar.MONTH), 2);  
      cal.add((Calendar.YEAR), 4);  
      cal.add((Calendar.DAY_OF_MONTH), 24);  
      cal.add((Calendar.HOUR), 5);  
      cal.add((Calendar.MINUTE), 60);  
      cal.add((Calendar.SECOND), 360);  
Calendar cal2 = (Calendar) cal.clone();  
      // display the copy  
      System.out.println("Cloned calendar object : " + cal2.getTime());  
}  
} 

输出结果为：

Mon Jul 30 09:47:25 PDT 2018
Cloned calendar object : Mon Oct 24 15:53:25 PDT 2022