一.通过idea建立工程
1.png
2.png
3.png
4.png
二.配置文件
1.在resources文件夹下建立config文件夹，并创建mybatis-config.xml，代码如下：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<package name="com.wyh.springbootmybatisdemo.pojo"/>
</typeAliases>
<!--<mappers>-->
<!--</mappers>-->
</configuration>
2.在resources文件夹下建立mapper文件夹,并创建UserMapper.xml，代码如下:
<?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.wyh.springbootmybatisdemo.mapper.UserMapper">
<resultMap id="BaseResultMap" type="com.wyh.springbootmybatisdemo.pojo.User" >
<result column="id" property="id" />
<result column="name" property="name" />
<result column="password" property="password" />
</resultMap>
<select id="findById" resultMap="BaseResultMap">
select * from user where id = #{id}
</select>
<select id="findAll" resultMap="BaseResultMap">
select * from user
</select>
</mapper>
3.application.properties配置文件代码如下：
spring.datasource.url=jdbc:mysql://localhost:3306/webtest?characterEncoding=utf-8&useSSL=true&serverTimezone=GMT
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name= com.mysql.cj.jdbc.Driver
mybatis.config-location=classpath:config/mybatis-config.xml
mybatis.mapper-locations= classpath:mapper/*.xml
如果遇到下列错误，是由于MySQL 这个jar 包依赖类型默认是runtime ，
也就是说只有运行时生效，所以虽然这里报错，但是不影响你代码运行。
error.png
在pom.xml文件内将依赖改成compile就行
image.png
三.pojo类
在com.wyh.springbootmybatisdemo下建立pojo包，并在该包下建立User类
import java.io.Serializable;
public class User implements Serializable {
private static final long serialVersionUID = 1L;
private Long id;
private String name;
private String password;
public User() {
}
public User(Long id, String name, String password) {
this.id = id;
this.name = name;
this.password = password;
}
public static long getSerialVersionUID() {
return serialVersionUID;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
四.mapper
在com.wyh.springbootmybatisdemo下建立mapper包，并在该包下建立UserMapper接口
import com.wyh.springbootmybatisdemo.pojo.User;
import java.util.List;
public interface UserMapper {
User findById(Long id);
List<User> findAll();
}
五.controller控制器
在com.wyh.springbootmybatisdemo下建立controller包,并在该包下建立UserController类
import com.wyh.springbootmybatisdemo.mapper.UserMapper;
import com.wyh.springbootmybatisdemo.pojo.User;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
@RestController
@RequestMapping("/user")
public class UserController {
@Resource
private UserMapper userMapper;
@GetMapping
public User findUser(@RequestParam(value = "id") Long id){
return userMapper.findById(id);
}
}
六.启动类
在启动类上面加入扫描的注解
@MapperScan("com.wyh.springbootmybatisdemo.mapper")
如下所示：
@SpringBootApplication
@MapperScan("com.wyh.springbootmybatisdemo.mapper")
public class SpringbootmybatisdemoApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootmybatisdemoApplication.class, args);
}
}
七.数据库
建立webtest数据库，user表结构如下：
mysql_user表
八.项目结构目录
image.png
九. 启动springboot项目并测试
在浏览器url输入http://localhost:8080/user?id=1
test.png
测试成功！！！
