java 关键字 clone

1. 最简单的clone例子

/**
 * 
 */
package com.study.effective.clone;
/**   
 * 简单的Clone例子
 * 1. 必须实现Cloneable接口,这个类才可以调用clone方法,不然会报错
 * @className ：CloneClass  
 * @package : com.study.effective 
 * @Description ：最简单的Clone例子.   
 * @author：lgf   
 * @date ：2012 二月 1  10:29:09          
 * @version : 1.0
 */
public class CloneClass implements Cloneable{
	// 定义测试属性
	private int intValue;
	private String strValue;
	
	public int getIntValue() {
		return this.intValue;
	}

	public void setIntValue(int intValue) {
		this.intValue = intValue;
	}

	public String getStrValue() {
		return this.strValue;
	}

	public void setStrValue(String strValue) {
		this.strValue = strValue;
	}

	/**
	 * 克隆测试
	 * 最简单的例子
	 * 就是直接调用自身的super.clone();
	 */
	public Object clone(){
		CloneClass o = null;
		try {
			o = (CloneClass)super.clone();
		} catch (CloneNotSupportedException e) {
			e.printStackTrace();
		}
		return o;
	}
	
	public static void main(String[] args) {
		CloneClass c1 = new CloneClass();
		c1.setIntValue(1);
		c1.setStrValue("c1 的值");
		
		CloneClass c2 = (CloneClass)c1.clone();
		c2.setIntValue(2);
		c2.setStrValue("c2 的值");
		
		System.out.println(c1.getIntValue()); 	//  1
		System.out.println(c1.getStrValue());	//  c1 的值
		System.out.println(c2.getIntValue());	//	2
		System.out.println(c2.getStrValue());	//	c2 的值
		// c1 和 c2 有不同的地址
		System.out.println(c1);//com.study.effective.clone.CloneClass@de6ced
		System.out.println(c2);//com.study.effective.clone.CloneClass@c17164
		
	}
}

2. 影子克隆

package com.study.effective.clone;

/**
* @className ：UnCloneClass1  
* @package : com.study.effective.clone 
* @Description ：未重载clone方法   
* @author：lgf   
* @date ：2012 二月 1  11:08:26          
* @version : 1.0
 */
class UnCloneClass1{
	public String value;
}

/**   
 * 
 * @className ：ShadowClone  
 * @package : com.study.effective 
 * @Description ：影子克隆的例子   
 * @author：lgf   
 * @date ：2012 二月 1  10:40:58          
 * @version : 1.0
 */
public class ShadowClone implements Cloneable{	
	//基本属性
	public int intValue;
	//对象属性
	public UnCloneClass1 unClass;
	
	public ShadowClone(UnCloneClass1 unClass,int intValue){
		this.unClass = unClass;
		this.intValue = intValue;
	}
	
	public Object clone(){
		ShadowClone o = null;
		try {
			o = (ShadowClone)super.clone();
		} catch (CloneNotSupportedException e) {
			e.printStackTrace();
		}
		return o;
	}
	
	public static void main(String[] args) {
		// 影子克隆
		UnCloneClass1 cloClass = new UnCloneClass1();
		cloClass.value = "影子克隆例子";
		ShadowClone shadowclone = new ShadowClone(cloClass,10);
		ShadowClone shadow = (ShadowClone)shadowclone.clone();
		
		// 打印值UnCloneClass1 类的 value值
		System.out.println(shadowclone.unClass.value); 	//影子克隆例子
		System.out.println(shadow.unClass.value);		//影子克隆例子
		
		shadowclone.unClass.value = "克隆类的新值";
		System.out.println(shadowclone.unClass.value); 	//克隆类的新值
		System.out.println(shadow.unClass.value);		//克隆类的新值
		
		// 查看地址
		System.out.println(shadowclone); 	//effective.clone.ShadowClone@c17164
		System.out.println(shadow); 		//effective.clone.ShadowClone@1fb8ee3
		
		//effective.clone.UnCloneClass1@61de33 两个类的unClass 属性指向同一个地址
		System.out.println(shadowclone.unClass); 
		System.out.println(shadow.unClass);
	}
}

3. 深度克隆

package com.study.effective.clone;

/**
* @className ：UnCloneClass2  
* @package : com.study.effective.clone 
* @Description ：实现重载clone 方法的对象 
* @author：lgf   
* @date ：2012 二月 1  11:10:31          
* @version : 1.0
 */
class UnCloneClass2 implements Cloneable{
	public String value;
	/**
	 * 类本身重载clone方法
	 */
	public Object clone(){
		UnCloneClass2 o = null;
		try {
			o = (UnCloneClass2)super.clone();
		} catch (CloneNotSupportedException e) {
			e.printStackTrace();
		}
		return o;
	}
}
/**   
 * 
 * @className ：DepthClone  
 * @package : com.study.effective 
 * @Description ：深度克隆   
 * @author：lgf   
 * @date ：2012 二月 1  10:59:17          
 * @version : 1.0
 */
public class DepthClone implements Cloneable{
	public int intValue;
	public UnCloneClass2 unClass;
	
	public DepthClone(UnCloneClass2 unClass,int intValue){
		this.unClass = unClass;
		this.intValue = intValue;
	}
	
	public Object clone(){
		DepthClone o = null;
		try {
			o = (DepthClone)super.clone();
		} catch (CloneNotSupportedException e) {
			e.printStackTrace();
		}
		o.unClass = (UnCloneClass2)unClass.clone();
		return o;
	}
	
	public static void main(String[] args) {
		// 影子克隆
		UnCloneClass2 cloClass = new UnCloneClass2();
		cloClass.value = "影子克隆例子";
		DepthClone depthClone = new DepthClone(cloClass,10);
		DepthClone depth = (DepthClone)depthClone.clone();
		
		// 打印值UnCloneClass1 类的 value值
		System.out.println(depthClone.unClass.value); 	//影子克隆例子
		System.out.println(depth.unClass.value);		//影子克隆例子
		
		depthClone.unClass.value = "克隆类的新值";
		System.out.println(depthClone.unClass.value); 	//克隆类的新值
		System.out.println(depth.unClass.value);		//影子克隆例子
		
		// 查看地址
		System.out.println(depthClone); 	//effective.clone.ShadowClone@c17164
		System.out.println(depth); 		//effective.clone.ShadowClone@1fb8ee3
		
		// 指向不同的地址
		System.out.println(depthClone.unClass);  //effective.clone.UnCloneClass2@61de33
		System.out.println(depth.unClass);		//effective.clone.UnCloneClass2@14318bb

	}
}