本文讲述Spring Boot如何通过mybatis-spring-boot-starter集成Mybatis，并给出一个简单的示例。
假设数据库中有t_user表，里面有id和username两个字段。
| id | username |
|---|---|
| 1 | zhangsan |
| 2 | lisi |
1. 配置pom.xml
引入mybatis-spring-boot-starter。
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.3.5.RELEASE</version>
<relativePath />
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.20</version>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<scope>runtime</scope>
</dependency>
</dependencies>
2. 在application.properties中增加mybatis配置
#mybatis配置
#Mapper.xml所在的位置
mybatis.mapper-locations=classpath*:mappers/*Mapper.xml
#entity扫描的包名
mybatis.type-aliases-package=com.example.entity
application.properties中关于数据源的配置可以参考：http://www.jianshu.com/p/c8a01ae9f779
3. 代码
3.1 User实体
根据application.properties中的定义，包名为com.example.entity
public class User {
private Integer id;
private String username;
//省略了setters & getters
}
3.2 UserMapper接口
注意不要忘记写@Mapper。
@Mapper
public interface UserMapper {
User selectUser(Integer id);
List<User> selectAllUsers();
void insertUser(User user);
void updateUser(User user);
void deleteUser(User user);
}
3.3 UserMapper.xml
根据application.properties中的定义，UserMapper.xml位于src/main/resources/mappers目录下。
<?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.example.dao.UserMapper">
<resultMap type="User" id="userResultMap">
<id property="id" column="id" />
<result property="username" column="username" />
</resultMap>
<select id="selectUser" resultType="User" resultMap="userResultMap">
select id, username from t_user where id = #{id}
</select>
<select id="selectAllUsers" resultType="list" resultMap="userResultMap">
select id, username from t_user
</select>
<insert id="insertUser" parameterType="User">
insert into t_user (id, username ) values (#{id},#{username})
</insert>
<update id="updateUser" parameterType="User">
update t_user
<set>
<if test="username != null ">
username = #{username},
</if>
</set>
where id = #{id}
</update>
<delete id="deleteUser" parameterType="User">
delete from t_user where id = #{id}
</delete>
</mapper>
3.4 UserController
@RestController
@RequestMapping("/user")
public class UserController {
@Autowired
UserMapper userMapper;
@RequestMapping(value = "/add.do", method = RequestMethod.POST)
public User add(@RequestParam(value = "id", required = true) Integer id,
@RequestParam(value = "username", required = true) String username) {
User user = new User();
user.setId(id);
user.setUsername(username);
userMapper.insertUser(user);
return user;
}
@RequestMapping(value = "/query.do", method = RequestMethod.GET)
public User query(@RequestParam(value = "id", required = true) Integer id) {
return userMapper.selectUser(id);
}
}
3.5 访问验证
我们可以通过地址来验证查询：http://localhost:8080/user/query.do?id=1
也可以使用Swagger来访问Controller验证代码，Spring Boot 集成 Swagger可以参考：http://www.jianshu.com/p/8ee632047496
spring-boot-starter地址：https://github.com/mybatis/spring-boot-starter
mybatis-spring地址：http://www.mybatis.org/spring/zh/index.html
