一、pom.xml 配置

  <!-- mybatis -->
  <dependency>
     <groupId>org.mybatis.spring.boot</groupId>
     <artifactId>mybatis-spring-boot-starter</artifactId>
     <version>2.2.2</version>
  </dependency>
   <!-- MySQL连接-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>

二、application.yml 配置

spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/database?useUnicode=true&characterEncoding=UTF-8
    username: root
    password: password 
    driver-class-name: com.mysql.cj.jdbc.Driver

三、创建DAO类做数据持久层的工作与数据库进行交互

@Mapper
public interface UsersDAO {

    /**
     * 重新users表中的所有数据
     *
     * @return 返回查看到的数据
     */
    @Select("select * from users")
    List<UsersModel> selectAll();
}

四、创建数据实体类

public class UsersModel{
    private long usersId;
    private String usersName,usersToken;

    public long getUsersId() {
        return usersId;
    }

    public void setUsersId(long usersId) {
        this.usersId = usersId;
    }

    public String getUsersName() {
        return usersName;
    }

    public void setUsersName(String usersName) {
        this.usersName = usersName;
    }

    public String getUsersToken() {
        return usersToken;
    }

    public void setUsersToken(String usersToken) {
        this.usersToken = usersToken;
    }
}

public class BaseModel {
    public BaseModel(boolean state, String msg, Object object) {
        this.state = state;
        this.msg = msg;
        this.object = object;
    }
    private boolean state;
    private String msg;
    private Object object;

    public boolean isState() {
        return state;
    }

    public void setState(boolean state) {
        this.state = state;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public Object getObject() {
        return object;
    }

    public void setObject(Object object) {
        this.object = object;
    }

五、创建Service类负责业务模块的逻辑应用设计

@Service
public class UsersService {
    @Autowired
    private UsersDAO usersDAO;
    public List<UsersModel> selectAll(){
        return usersDAO.selectAll();
    }
}

六、创建Controller

@RestController
public class HomeController {
    @Autowired
    private UsersService usersService;
    @RequestMapping(value = "/",method = RequestMethod.GET)
    public BaseModel index(){
        return new BaseModel(true,null,usersService.selectAll());
    }
}

七、启动项目，发起请求。