SpringBoot整合Mybatis总结

导入依赖，看清楚了，别导错

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.2.0</version>
</dependency>

配置application.yml

spring:
  profiles:
    active: dev

mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.feige.domin

配置application-dev.yml

server:
  port: 8080
 
 #mybatis setting
spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8
    driver-class-name: com.mysql.cj.jdbc.Driv

项目有好多环境，开发环境，测试环境，生产环境，每个环境的参数不同，所以我们就可以把每个环境的参数配置到不同的yml文件中。
application-dev.yml：开发环境
application-test.yml：测试环境
application-prod.yml：生产环境
至于哪个具体的配置文件会被加载，需要在application.yml文件中通过spring.profiles.active属性来设置。

SpringBoot启动类

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
// 扫描包中的类，加载入spring内。
@ComponentScan(basePackages = {"com.feige.*",})
@SpringBootApplication
//这个必须要有，不然找不到mapper
@MapperScan("com.feige.*")
public class MySpringBoootApplication {

	public static void main(String[] args) {
		SpringApplication.run(MySpringBoootApplication.class, args);
	}
}

Mapper.java

import org.springframework.stereotype.Repository;

import com.feige.domin.User;

@Repository
public interface UserMapper {
	User selectById(String id);
}

Mapper.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.feige.dao.UserMapper">

    <select id="selectById" resultType="com.feige.domin.User" parameterType="java.lang.String">
        select * from user where id = #{0}
    </select>

</mapper>

Controller.java

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.feige.dao.UserMapper;
import com.feige.domin.User;

@RestController
public class UserController {
	
	@Autowired
	private UserMapper mapper;
	
	@PostMapping("/person/select")
	public User select(@RequestParam String id) {
		User user = mapper.selectById(id);
		System.out.println(user);
		return user;
	}
}

项目结构

Postman测试