SpringBoot整合mybatis步骤

Posted 2021-03-02 文戌

1.创建项目

创建项目时勾选依赖
web依赖

lombok

mysql和mybatis

或者直接在pom.xml中导入依赖(mybatis/mysql/)

   <!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
   <dependency>
       <groupId>org.mybatis.spring.boot</groupId>
       <artifactId>mybatis-spring-boot-starter</artifactId>
       <version>2.1.1</version>
   </dependency>
   <dependency>
       <groupId>mysql</groupId>
       <artifactId>mysql-connector-java</artifactId>
   </dependency>

2.配置数据库连接(在application.properties)

ps : 如果整合Druid只需要把这一步省略,将数据库连接交给Druid编写

详见:

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

3.配置别名和mapper.xml路径

#整合mybatis
mybatis.type-aliases-package=com.yue.pojo
#此处的地址与下文第六步的地址需要一样
mybatis.mapper-locations=classpath:mapper/*.xml

4.编写User实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private int id;
    private String name;
    private String pwd;
}

5.编写mapper接口

//这个注解表示了这是一个 mybatis 的 mapper 类
@Mapper
@Repository
public interface UserMapper {
    List<User> getAll();
    User getUserById(int id);
    int addUser(User user);
}

6.在resource/mapper下编写mapper.xml文件

<?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.yue.dao.UserMapper">
    <select id="getAll" resultType="User">
        select * from mybatis.user
    </select>
    <select id="getUserById" parameterType="int" resultType="User">
        select * from mybatis.user where id = #{id}
    </select>
    <insert id="addUser" parameterType="User">
        insert into mybatis.user (id, name, pwd) values (#{id},#{name},#{pwd});
    </insert>

</mapper>

7.测试(由于此业务比较简单,故省略service层)

@RestController
public class UserController {
	//如果前面的mapper.xml的地址没有配错的话,这里也就顺利的使用自动装配
    @Autowired
    UserMapper userMapper;

    @RequestMapping("/getall")
    public List<User> getAll(){
        List<User> all = userMapper.getAll();
        return all;
    }
}

成功