你好，我在做一个简单的spring应用程序，由于某种原因出现了这个错误：
类型不匹配：无法从对象转换为accountdao
我有三节课，分别是：

package com.luv2code.aopdemo.dao;

import org.springframework.stereotype.Component;

@Component
public class AccountDAO {

    public void addAccount() {

        System.out.println(getClass() + ": DOING MY DB WORK: ADDING AN ACCOUNT");

    }

}

演示配置：

package com.luv2code.aopdemo;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;

@Configuration
@EnableAspectJAutoProxy
@ComponentScan("com.luv2code.aopdemo")
public class DemoConfig {

}

和maindemoapp：

package com.luv2code.aopdemo;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import com.luv2code.aopdemo.dao.AccountDAO;

public class MainDemoApp {

    public static void main(String[] args) {

        //read spring config java class
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(DemoConfig.class);

        //get the bean from spring container
        AccountDAO theAccountDAO = context.getBean("accountDAO", AccountDAO.class); //THE PROBLE IS HERE

        //call the business method
        theAccountDAO.addAccount();

        //close the context
        context.close();

    }

}

错误在maindemoapp中的accountdao theaccountdao=context.getbean（“accountdao”，accountdao.class）(只有后面的部分是红色的）