package com.dayuanit.service;

public abstract class UserService {

    public void login(String userName, String pwd){

        System.out.println("login begin");

        first();

        second();

        third();

        System.out.println("login over");

    }

    public void first(){

        System.out.println("login 1");

    }

    protected abstract void second();

    public void third(){

        System.out.println("login 3");

    }

}

package com.dayuanit.authen;

import com.dayuanit.service.UserService;

public class AlipayAuthen extends UserService{

    @Override

    protected void second(){

        System.out.println("alipay login 2");

    }

}

package com.dayuanit.authen;

import com.dayuanit.service.UserService;

public class WeiXinAuthen extends UserService{

    @Override

    public void second(){

        System.out.println("weixin login 2");

    }

}

package com.dayuanit;

import com.dayuanit.authen.AlipayAuthen;

import com.dayuanit.authen.WeiXinAuthen;

public class Test {

    public static void main(String[] args) {

        //new UserService().login("tom", "111");

        new WeiXinAuthen().login("tom","111");

        System.out.println("--------------------------------");

        new AlipayAuthen().login("tom", "111");

    }

}