1.先创建一个string boot项目

2.写好项目名包名 选择好java版本 点击Next  勾选在web下的Spring Web(Spring Mvc)

 3.Mybatis 整合

将版本改为  2.1.3.RELEASE

在pom.xml中添加依赖

         <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><scope>runtime</scope></dependency>

4.刷新maven后 在resources下添加配置文件 application.yml 

spring:datasource:url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&serverTimezone=CTTusername: root  #数据库账户password: root  #数据库密码driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:mapper-locations: classpath:mapper/*.xml  #对应mapper映射xml文件所在路径type-aliases-package: com.xxxx.entity  #对应实体类路径

 5. 接下来连接数据库  在配置文件中写入数据库的地址和数据库名 集成Mybatis就完成

 6.进行测试

UserMapper.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.test.demo.mapper.UserMapper"><select id="listAll" resultType="com.test.demo.entity.User">select * from user</select>
</mapper>

 User文件

package com.test.demo.entity;
public class User {private Integer id;private String name;private Integer age;@Overridepublic String toString() {return "User{" +"id=" + id +", name='" + name + '\'' +", age=" + age +'}';}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}
}

 UserMapper文件

package com.test.demo.mapper;
import com.test.demo.entity.User;
import java.util.List;
public interface UserMapper {List<User> listAll();
}

UserController文件

package com.test.demo.controller;
import com.test.demo.entity.User;
import com.test.demo.mapper.UserMapper;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import javax.annotation.Resource;
import java.util.List;
@Controller
public class UserController {@Resourceprivate UserMapper userMapper;@RequestMapping("listAll")@ResponseBodypublic List<User> listAll(){return userMapper.listAll();}
}

查询 数据库为test的user表数据