Spring自动装配的理解

package main.daoImpl;

import main.dao.CommandDAO;
import main.db.DBAccess;
import main.entity.Command;
import main.entity.Message;
import org.apache.ibatis.session.SqlSession;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

/**
 * @program: Tradingplatform
 * @description:
 * @author: Robert_Wang
 * @create: 2018-09-07 21:47
 **/
@Repository
public class CommandDAOImpl implements CommandDAO {

    @Autowired
    private DBAccess dbAccess;


    @Override
    public List query(String name, String description) {
        List commandList = new ArrayList<>();
        SqlSession sqlSession = null;
        try {
            sqlSession = dbAccess.getSqlSession();
            Command commands = new Command();
            commands.setName(name);
            commands.setDescription(description);
            commandList = sqlSession.selectList("Command.queryCommandList",commands);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return commandList;
    }
}

现在这个类有一个@Repository标识， 并且内部有一个@Autowired，只要这个类被组件扫描到，spring会 自动生成bean,并且是连同dbAcess（只要dbAcess能在beanFactory中找到）。

但是如果同时还有手动去new CommandDAOImpl的话，并不会自动装配里面的dbAcess， 并且将原先的覆盖。