06.创建型————原型模式

package Create.e.Prototype;

//原型业务类  需要实现克隆接口
public class Dog implements Cloneable{
	public int legCounts;
	public Dog(int legCounts){
		this.legCounts = legCounts;
	}
	public void changeLegCounts(){
		this.legCounts *= 2;
	}
	public String toString(){
		return Integer.toString(this.legCounts);
	}
	@Override
	protected Object clone() throws CloneNotSupportedException {
		// TODO Auto-generated method stub
		Dog o = null;
		try{
			o = (Dog)super.clone();
		}catch(CloneNotSupportedException e){
			e.printStackTrace();
		}
		return o;
	}
	
}

　　

package Create.e.Prototype;

//原型复制类
public class DogClone implements Cloneable {
	public int legCounts;
	public Dog dog = new Dog(4);
	@Override
	protected Object clone() throws CloneNotSupportedException {
		// TODO Auto-generated method stub
		DogClone o = null ;
		try{
			o = (DogClone) super.clone();
		}catch(CloneNotSupportedException e){
			e.printStackTrace();
		}
		o.dog = (Dog)dog.clone();
		return o;
	}
	
}

　　

package Create.e.Prototype;

//业务调用类
public class Client {
	public static void main(String[] args) throws Exception{
		DogClone clone = new DogClone();
		clone.legCounts = 3;
		System.out.println("原来克隆狗的腿数:" + clone.legCounts);
		System.out.println("原来普通狗的腿数:" + clone.dog);
		
		DogClone clone1 = (DogClone)clone.clone();
		clone1.legCounts = 2;
		Dog dog = clone1.dog;
		dog.changeLegCounts();
		
		System.out.println("克隆后原来的克隆狗腿数：" + clone.legCounts);
		System.out.println("克隆后原来的普通狗腿数：" + clone.dog);
		
		System.out.println("克隆后的克隆狗腿数：" + clone1.legCounts);
		System.out.println("克隆后的普通狗腿数：" + clone1.dog);
	}
}

　　

优点：可以动态添加产品，并不会影响到整体的结构

缺点：每个原型类都需要配备一个克隆方法，这需要在设计初期就要通盘考虑清楚，因为如果在已有的类基础上再去添加克隆方法是比较困难的。另外就是如果需要实现深层次复制时，需要编写一定量的代码