6, mybatis-springboot整合mybatis

使用Spring Initializer快速构建

先去Spring Initializer官网 快速构建一个的springboot基础项目

配置选择

添加依赖

1. Spring Web
2. JDBC Api
3. MySql Driver
4. Mybatis FrameWork

点击创建(CREATE), 下载项目

构建简单http服务

添加controller

@RestController
@RequestMapping("/hi")
public class HelloController {

	@RequestMapping("/{name}")
	public String hello(@PathVariable("name") String name) {
		return "hello " + name + "! welcome!!!";
	}
}

测试

运行访问 http://127.0.0.1:8080/hi/xiaodoubi, 发现运行ok, 能正常访问

hello xiaodoubi! welcome!!!

运行前, 注释掉pom.xml中关于数据库的库, jdbc, driver等依赖, 后面集成了数据库在打开

集成mybatis

依然使用我们之前的数据库,表, 打开上面注释掉的相关依赖

mybatis 生成器

使用mybatis generator生成xml, mapper以及实体类

User.java, UserMapper.xml, 生成详情见前面教程

添加UserController

@RestController
@RequestMapping("/user")
public class UserController {

	@Autowired
	private UserMapper userMapper;

	@RequestMapping("/{id}")
	public User selectById(@PathVariable("id") Integer id) {
		return userMapper.selectById(id);
	}

}

配置application.yml

删掉applicaiton.properties, 新建application.yml(更简洁)

server:
  port: 8080

# spring数据库连接, 仅为测试, 未使用数据库连接池配置
spring:
    datasource:
        name: test
        url: jdbc:mysql://172.28.149.239:3306/test?useSSL=false
        username: root
        password: root
        driver-class-name: com.mysql.cj.jdbc.Driver

# mybatis的mapping的xml文件
mybatis:
  mapper-locations: classpath:mapping/*.xml

运行

运行Application, 发现报错

No qualifying bean of type 'top.itkaoti.mybatis.springbootmybatistest.mapper.UserMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

报错原因:添加UserMaper注入是找不到bean, 因为mapper没有被spring扫描到,无法被spring管理

添加mapper包扫描, 让spring去管理这些mapper

@SpringBootApplication
@MapperScan({"top.itkaoti.mybatis.springbootmybatistest.mapper"})
public class SpringBootMybatisTestApplication {

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

}

访问 http://127.0.0.1:8080/user/1

{"id":1,"name":"xiaodoubi","age":27,"sex":1}

SpringBootMybatisTest项目地址