在使用spring連線資料庫的時候，採用springboot+mybatis的方式連線資料庫
首先在pom.xml檔案中新增mybatis的啟動器和SQL server資料庫的資料庫驅動jar

<dependency>
            <groupId>com.microsoft</groupId>
            <artifactId>sqljdbc4</artifactId>
            <version>3.0</version>
        </dependency
 
>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>

然後在resources/application.properties檔案中配置資料庫 的基本資訊。

#SQL server
 

spring.datasource.url=jdbc:sqlserver://192.168.5.28:1438;DatabaseName=dawnCar
spring.datasource.username=sa
spring.datasource.password=123
spring.datasource.driver-class-name=com.microsoft.sqlserver.jdbc.SQLServerDriver

接下來是在dao層寫mapper檔案

package com.dawn.VehicleNetworkSystem.Mapper;

import java.util
 
.List;

import org.apache.ibatis.annotations.Select;

import com.dawn.VehicleNetworkSystem.pojo.User;

public interface UserMapper {
    /*這些不需要加mapping*/
    //查詢語句
    @Select("select * from dawnCar.dbo.info_user")
   List<User> queryAll();
}

為了能找到對應的mapper，需要在springboot主程式新增掃描包的註解@MapperScan

package com.dawn.VehicleNetworkSystem;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Controller;

@SpringBootApplication
@MapperScan(basePackages="com.dawn.VehicleNetworkSystem.Mapper")
public class VehicleNetworkSystemApplication {

    public static void main(String[] args) {
        SpringApplication.run(VehicleNetworkSystemApplication.class, args);
    }
}

然後就可去測試是否能從資料庫中取值

package com.dawn.VehicleNetworkSystem;


import java.util.List;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.dawn.VehicleNetworkSystem.Mapper.UserMapper;
import com.dawn.VehicleNetworkSystem.pojo.User;

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class VehicleNetworkSystemApplicationTests {
  @Autowired
  private UserMapper userMapper;
    @Test
    public void querytest() {
        List<User> users=userMapper.queryAll();
        System.out.println(users);

    }

}

可以將資訊反饋到網頁，具體做法如下

//這是service曾的程式碼，抽取這一層的作用就是為了解耦
package com.dawn.VehicleNetworkSystem.Service;

import java.util.List;

import com.dawn.VehicleNetworkSystem.pojo.User;

public interface UserService {
 public boolean checkLogin(String userName,String passWord);
 public List<User> queryAll();

}
//這是service實現類的程式碼
import java.util.List;

import org.springframework.stereotype.Service;

import com.dawn.VehicleNetworkSystem.Mapper.UserMapper;
import com.dawn.VehicleNetworkSystem.Service.UserService;
import com.dawn.VehicleNetworkSystem.pojo.User;
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;
    @Override
    public boolean checkLogin(String userName, String passWord) {
    if(userName.equals("lyj")&&passWord.equals("123")) return true;
        return false;
    }

    @Override
    public List<User> queryAll() {
        List<User> user=userMapper.queryAll();
        System.out.println(user);
        return  user;
    }

接下來controller層就不需要寫下去了。可以參照之前寫法繼續。具體的檔案結構如下