06.建立型————原型模式

package Create.e.Prototype;

//原型業務類  須要實現克隆接口
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;

//原型複製類
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;

//業務調用類
public class Client {
	public static void main(String[] args) throws Exception{
		DogClone clone = new DogClone();
		clone.legCounts = 3;
		System.out.println("原來克隆狗的腿數:" + clone.legCounts);
		System.out.println("原來普通狗的腿數:" + clone.dog);
		
		DogClone clone1 = (DogClone)clone.clone();
		clone1.legCounts = 2;
		Dog dog = clone1.dog;
		dog.changeLegCounts();
		
		System.out.println("克隆後原來的克隆狗腿數：" + clone.legCounts);
		System.out.println("克隆後原來的普通狗腿數：" + clone.dog);
		
		System.out.println("克隆後的克隆狗腿數：" + clone1.legCounts);
		System.out.println("克隆後的普通狗腿數：" + clone1.dog);
	}
}

　　

 

優勢：能夠動態添加產品，並不會影響到總體的結構

缺點：每一個原型類都須要配備一個克隆方法，這須要在設計初期就要通盤考慮清楚，由於若是在已有的類基礎上再去添加克隆方法是比較困難的。另外就是若是須要實現深層次複製時，須要編寫必定量的代碼