一、前置条件

先创建好一个最简单的spring boot项目，可参考之前章节的源代码或直接自己创建一个。

二、创建数据库

创建数据库

create database springboot;

创建用户表tbl_user并插入测试数据

CREATE TABLE `tbl_user` ( `user_id` bigint(20) NOT NULL, `user_name` varchar(50) DEFAULT NULL, `user_age` int(11) DEFAULT NULL, PRIMARY KEY (`user_id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; INSERT INTO `tbl_user` VALUES (1, '张三', 27); INSERT INTO `tbl_user` VALUES (2, '李四', 30); INSERT INTO `tbl_user` VALUES (3, '王五', 20);

脚本sql在源码的db文件夹中。

三、引入mybatis依赖

<!-- mybatis --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.2</version> </dependency> <!-- mysql --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency>

四、编写代码

1、创建实体

package com.songguoliang.mybatis.entity; /** * @Description * @Author sgl * @Date 2018-05-02 14:59 */ public class User { private Long userId; private String userName; private Integer userAge; public Long getUserId() { return userId; } public void setUserId(Long userId) { this.userId = userId; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public Integer getUserAge() { return userAge; } public void setUserAge(Integer userAge) { this.userAge = userAge; } }

2、创建Mapper文件

在resources文件夹下创建mapper文件夹，然后在mapper文件夹里创建UserMapper.xml，内容如下：

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.songguoliang.mybatis.mapper.UserMapper"> <select id="getUsers" resultType="User"> SELECT * FROM tbl_user </select> </mapper>

3、创建Mapper(Dao)接口

package com.songguoliang.mybatis.mapper; import com.songguoliang.mybatis.entity.User; import java.util.List; /** * @Description * @Author sgl * @Date 2018-05-02 15:02 */ public interface UserMapper { List<User> getUsers(); }

4、创建Service

package com.songguoliang.mybatis.service; import com.songguoliang.mybatis.entity.User; import com.songguoliang.mybatis.mapper.UserMapper; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; /** * @Description * @Author sgl * @Date 2018-05-02 15:01 */ @Service public class UserService { @Autowired private UserMapper userMapper; public List<User> getUsers() { return userMapper.getUsers(); } }

5、创建controller

package com.songguoliang.mybatis.controller; import com.songguoliang.mybatis.entity.User; import com.songguoliang.mybatis.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; import java.util.List; /** * @Description * @Author sgl * @Date 2018-05-02 14:59 */ @RestController public class UserController { @Autowired private UserService userService; @GetMapping("/users") public List<User> lists() { return userService.getUsers(); } }

五、配置mybatis

1、配置数据源

在application.properties配置文件中添加如下代码：

## 数据源配置 spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf-8&useSSL=false spring.datasource.username=root spring.datasource.password=root spring.datasource.driver-class-name=com.mysql.jdbc.Driver

2、添加mybatis配置

在application.properties配置文件中添加mybatis的配置，如下代码：

# mybatis mybatis.type-aliases-package=com.songguoliang.mybatis.entity mybatis.mapper-locations=classpath:mapper/*.xml mybatis.configuration.map-underscore-to-camel-case=true mybatis.type-aliases-package：别名类(实体类)所在包mybatis.mapper-locations：mapper文件所在文件夹mybatis.configuration.map-underscore-to-camel-case：采用驼峰命名方式转换

3、扫描Mapper接口

在启动类上添加注解@MapperScan("com.songguoliang.mybatis.mapper") ，注意MapperScan的包路径(org.mybatis.spring.annotation.MapperScan)，后面章节和Mapper4集成时会修改导入的包。

package com.songguoliang.mybatis; import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; /** * @Description * @Author sgl * @Date 2018-05-02 14:51 */ @SpringBootApplication @MapperScan("com.songguoliang.mybatis.mapper") public class MybatisApplication { public static void main(String[] args) { SpringApplication.run(MybatisApplication.class, args); } }

六、测试

启动服务，浏览器输入http://localhost:8080/users ,可看到如下内容：

源码： github 码云