原型模式

public class Cookie implements Cloneable{
    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}

public class CookieA extends Cookie{
}

public class CookieMachine {
    private Cookie cookie;//必须可复制,否则makeCookie会抛出异常
    public CookieMachine(Cookie cookie){
        this.cookie = cookie;
    }
    public Cookie makeCookie(){
        try {
            return (Cookie)cookie.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return null;
    }
}

//测试
public class Client {
    public static void main(String[] args){
        CookieMachine cookieMachine = new CookieMachine(new CookieA());
        System.out.println(cookieMachine.makeCookie());
        System.out.println(cookieMachine.makeCookie());
    }
}