springboot配置mybatis
1.创建maven项目
2.pom.xml添加配置依赖
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.6.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.1.6.RELEASE</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.6</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.6</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>2.0.6.RELEASE</version>
</plugin>
</plugins>
</build>
</project>
3.配置文件
resource资源路径下,创建:application.properties
添加数据库连接
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/day21?useUnicode=true&characterEncoding=UTF-8&useSSL=false
#day21是你的数据库的库名
spring.datasource.username=root
spring.datasource.password=密码
#读取你mapper包下面的所有XxxMapper.xml文件
mybatis.mapper-locations=common-mapper/classpath:com.jd.dal.mapper
4.创建数据库中表和添加数据
数据库下,创建表
CREATE TABLE `user` (
`ID` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '用户id',
`NAME` varchar(32) NOT NULL COMMENT '用户名',
`AGE` int(11) DEFAULT NULL COMMENT '年龄',
PRIMARY KEY (`ID`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC COMMENT='用户';
添加内容
insert into user (NAME,AGE) values('mjp',18);
insert into user (NAME,AGE) values('wxx',23);
5.创建User实体类
com.jd.dal.entity包中创建类(需要plugin lombok插件,因为要用到@Data等注解,可以自行百度lombok插件的安装)
@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
private Integer id;
private String name;
private Integer age;
}
6.创建springboot启动类
在com.jd包下面创建
@SpringBootApplication
public class ApplicationLoader {
public static void main(String[] args) {
SpringApplication.run(ApplicationLoader.class, args);
}
}
7.创建UserController类,用于测试
在com.jd.controller包下面创建
@RestController
public class UserController {
@Autowired
private UserMapper mapper;
@GetMapping("/select")
public List<User> query(){
return userService.selectUser();
}
}
8.创建UserMapper
在com.jd.dal.mapper包下,创建UserMapper接口,并加上@Mapper注解
@Mapper
public interface UserMapper{
List<User> selectUser();
}
9.创建UserMapper.xml
在resource资源路径下,创建包:com.jd.dal.mapper(注意创建包时的书写方式为:com/jd/dal/mapper,不要com.jd.dal.mapper,否则本地文件resource中仅有一个com.jd.dal.mapper的包,而非层级分明的包)
resource
jd
dal
mapper
UserMapper.xml
<?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.jd.dal.mapper.UserMapper">
<resultMap id="BaseResultMap" type="com.jd.dal.entity.User">
<id column="ID" property="id"/>
<result column="NAME" property="name"/>
<result column="AGE" property="age"/>
</resultMap>
<sql id="Base_Column_List">
ID, NAME,AGE
</sql>
<select id="selectUser" resultType="com.jd.lean.dal.entity.User">
select
<include refid="Base_Column_List"></include>
from user
</select>
</mapper>
10.测试
run启动类:ApplicationLoader类
浏览器输入:http://localhost:8080/select
[{
"id":1,"name":"mjp","age":18},{
"id":2,"name":"wxx","age":23}]