1.环境搭建

2.创建Maven项目

3.导入mybatis 依赖

<!--  mybatis      -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>

4.配置mybatis-config.xml文件（官网可查）

<?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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>


    <mappers>
        <mapper resource="com/cn/dao/UserMapper.xml"/>
    </mappers>

</configuration>

5.获取mybatis sqlSession对象

 

package com.cn.util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

//sqlSessionFactory---> sqlSession
public class MybatisUtils {

    static {
        try {
            //获取Mybatis sqlSession对象
            String resource = "org/mybatis/example/mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        }catch (IOException e){
            e.printStackTrace();
        }
    }
}

6.从sqlSessionFactory 中获取sqlSession

public class MybatisUtils {

    private static SqlSessionFactory sqlSessionFactory;

    static {
        try {
            //获取Mybatis sqlSession对象
            String resource = "org/mybatis/example/mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
             sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        }catch (IOException e){
            e.printStackTrace();
        }
    }

    //从sqlSessionFactory 中获取sqlSession
    //SqlSession 完全包含了面向数据库执行 SQL命令所需的所有方法

    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }
}

7.编写代码

        1.实体类；     

package com.cn.pojo;

public class User {
    private int id;
    private String name;
    private String pwd;

    public User() {
    }

    public User(int id, String name, String pwd) {
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", pwd='" + pwd + '\'' +
                '}';
    }
}

        2.Dao接口；

public interface UserDao {
    List<User> getUserList();
}

        3.实现接口类；

                不用实现接口类

        4.mapper.xml配置

<?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">
<!-- namespace 绑定一个对应的Dao接口/Mapper 接口 -->
<mapper namespace="com.cn.dao.UserDao">

    <select id="getUserList" resultType="com.cn.pojo.User">
        select * from mybatis.user;
    </select>

</mapper>

         5.在mybatis-config.xml文件配置mapper.xml文件路径

<?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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>


    <mappers>
        <mapper resource="com/cn/dao/UserMapper.xml"/>
    </mappers>

</configuration>

8. junit测试

public class UserDaoTest {

    @Test
    public void test(){
        //1.获得sqlSession对象
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        //2.执行 sql
        UserDao mapper = sqlSession.getMapper(UserDao.class);
        List<User> userList = mapper.getUserList();

        for (User user:userList){
            System.out.println(user);
        }

        //3.关闭sqlSession
        sqlSession.close();
    }
}

9.解决资源导出失败问题，在pom.xml文件配置

<!-- 在build中配置resources，来防止资源导出失败的问题    -->
    <build>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>true</filtering>
            </resource>
        </resources>
    </build>