5.2.3.1 引入pom依赖

导入mybatis相关依赖，如果需要的话，还需引入JDBC和MysqlConnector相关依赖

<!-- mybatis -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.0</version>
</dependency>
<!-- JDBC -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!-- MySQL连接器 -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

5.2.3.2 编写DAO实体类

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    public String id;
    public String name;
    public String pwd;
    public Integer gender;
}

5.2.3.3 编写Mapper接口

@Mapper 标记这是一个映射接口

import com.xietong.web.dao.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper
@Repository
public interface UserMapper {
    List<User> queryUserList();
    User queryUserById(int id);
    int addUser(User user);
    int deleteUser(int id);
    int updateUser(User user);
}

5.2.3.4 编写XML文件

在/resources/mybatis/mapper下新建mapper文件 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.xietong.web.mapper.UserMapper">
    <select id="queryUserList" resultType="User">
        select * from user
    </select>
    <select id="queryUserById" resultType="User">
        select * from user where id = #{id}
    </select>
    <insert id="addUser" parameterType="User">
        insert into user (id,name,pwd,gender) values (#{id}, #{name}, #{pwd}, $#{gender})
    </insert>
    <delete id="deleteUser" parameterType="int">
        delete * from user where id = #{id}
    </delete>
    <update id="updateUser" parameterType="User">
        update user set name = #{name}, pwd = #{pwd}, gender = #{gender} where id = #{ide}
    </update>
</mapper>

5.2.3.5 整合MyBatis

在配置文件中加入mybatis相关配置，使spring能够正确识别mapper.xml文件并加载对应的类

mybatis:
  mapper-locations: classpath:mybatis/mapper/*.xml
  type-aliases-package: com.xietong.web.dao

5.2.3.6 编写Controller类

import com.xietong.web.dao.User;
import com.xietong.web.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/mybatis")
public class MyBatisController {

    @Autowired
    private UserMapper userMapper;

    @RequestMapping("/queryAll")
    public List<User> queryAll(){
        List<User> userList = userMapper.queryUserList();
        return userList;
    }

    @RequestMapping("/getById")
    public User getById(@RequestParam int id){
        return userMapper.getUserById(id);
    }

    @RequestMapping("/addUser")
    public String addUser(){
        int count = userMapper.addUser(new User(7, "白骨精", "1234", 1));
        return count > 1 ? "ok" : "添加异常";
    }

    @RequestMapping("/updateUser")
    public String updateUser(){
        int count = userMapper.updateUser(new User(7, "白骨精", "12347890", 1));
        return count > 1 ? "ok" : "修改异常";
    }

    @RequestMapping("/deleteUser")
    public String deleteUser(){
        int count = userMapper.deleteUser(7);
        return count > 1 ? "ok" : "删除异常";
    }
}