工厂模式作业

1.工厂类一定需要将构造方法私有化吗，为什么？

　　不一定。看源码中有public修饰的，原因自己描述不了

2.用工厂模式设计支付业务场景，包含跨境支付，支付宝、微信、银联支付,并画出类图。

public interface IPayFactory {

    public IPayMethod createPayMethod();

}

public interface IPayMethod {

    public void prePay();

    public void pay();

    public void afterPay();
}

public class ZfbPayMethod implements IPayMethod {
    @Override
    public void prePay() {
        System.out.println("支付宝支付前准备");
    }

    @Override
    public void pay() {
        System.out.println("支付宝支付");
    }

    @Override
    public void afterPay() {
        System.out.println("支付宝支付后操作：向用户推送短信");
    }
}

public class WechatPayMethod implements IPayMethod {
    @Override
    public void prePay() {
        System.out.println("微信支付前准备");
    }

    @Override
    public void pay() {
        System.out.println("微信支付");
    }

    @Override
    public void afterPay() {
        System.out.println("微信支付后操作：向用户推送短信");
    }
}

public class UnionPayMethod implements IPayMethod {
    @Override
    public void prePay() {
        System.out.println("银联支付前准备");
    }

    @Override
    public void pay() {
        System.out.println("银联支付");
    }

    @Override
    public void afterPay() {
        System.out.println("银联支付后操作：向用户推送短信");
    }
}

public class InternationalPayMethod implements IPayMethod {
    @Override
    public void prePay() {
        System.out.println("跨境支付前准备");
    }

    @Override
    public void pay() {
        System.out.println("跨境支付");
    }

    @Override
    public void afterPay() {
        System.out.println("跨境支付后操作：向用户推送短信");
    }
}

public class ZfbPayFactory implements IPayFactory {
    @Override
    public IPayMethod createPayMethod() {
        return new ZfbPayMethod();
    }
}

public class Test {

    public static void main(String[] args) {
        IPayFactory factory = new ZfbPayFactory();
        IPayMethod payMethod = factory.createPayMethod();
        payMethod.prePay();
        payMethod.pay();
        payMethod.afterPay();
    }
}