Java设计模式七大原则之开闭原则详解

public class PayType {
    int type;
}

public class WxPay extends PayType{
    WxPay(){
        super.type = 1;
    }
}

public class ZfbPay extends PayType{
    ZfbPay(){
        super.type = 2;
    }
}

public class Pay {
    public void pay(PayType s) {
        if (s.type == 1) {
            wxPay(s);
        } else if (s.type == 2) {
            zfbPay(s);
        }
    }

    // 微信支付
    public void wxPay(PayType r) {
        System.out.println(" 正在微信支付中---支付成功 ");
    }

    // 支付宝支付
    public void zfbPay(PayType r) {
        System.out.println(" 正在支付宝支付中---支付成功");
    }

}

public class Test1 {
    public static void main(String[] args) {
        new Pay().pay(new WxPay());
        new Pay().pay(new ZfbPay());
    }
}

public abstract class PayTypeNew {

    int type;

    public abstract void pay();
}

public class WxPayNew extends PayTypeNew{
    WxPayNew(){
        super.type = 1;
    }

    @Override
    public void pay() {
        System.out.println(" 正在微信支付中---支付成功 ");
    }
}

public class ZfbPayNew extends PayTypeNew{
    ZfbPayNew(){
        super.type = 2;
    }

    @Override
    public void pay() {
        System.out.println(" 正在支付宝支付中---支付成功");
    }
}

public class PayNew {
    public void pay(PayTypeNew payTypeNew) {
        payTypeNew.pay();
    }
}

public class Test2 {
    public static void main(String[] args) {
       new PayNew().pay(new WxPayNew());
       new PayNew().pay(new ZfbPayNew());
    }
}