<?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>

    <!--别名-->

    <!-- 使用别名代替全限定名 -->

  <typeAliases>

         <typeAlias type="model.User" alias="user"/>

  </typeAliases>

  <!-- 数据库环境 -->

  <environments default="development">

  <environment id="development">

  <transactionManager type="JDBC"/>

  <dataSource type="POOLED">

     <property name="driver" value="com.mysql.cj.jdbc.Driver"/>

    <!--在xml中 &=&-->

     <property name="url" value="jdbc:mysql://localhost:3306/office?useSSL=false&serverTimezone=Hongkong"/>

     <property name="username" value="root"/>

     <property name="password" value="123456"/>

  </dataSource>

  </environment>

  </environments>

  <!-- 映射文件 -->

  <mappers>

  <!-- 映射文件存放的位置 -->

  <mapper resource="mapper/UserMapper.xml"/>

  </mappers>

  </configuration>

import java.io.IOException;

import java.io.InputStream;

import org.apache.ibatis.io.Resources;

import org.apache.ibatis.session.SqlSessionFactory;

import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class SqlSessionFactorytest {

	//定义参数

	public static SqlSessionFactory sqlSessionFactory=null;

	//定义配置文件

	public static String resource="mybatis-config.xml";

	public static InputStream inputStream;

//构建SesseionFactory

	public static SqlSessionFactory getSqlSessionFactoryBuider() {

		try {

			//读取配置文件

			inputStream=Resources.getResourceAsStream(resource);

			System.out.println("配置文件加载成功！！");

			//SqlSessionFactoryBuilder通过输入流的相关配置得到sqlSessionFactory

		}catch(IOException e) {

			e.printStackTrace();

		}

		sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);

		System.out.println("sqlSessionFactory创造成功！！");

		return sqlSessionFactory;

	}

}

public interface UserDao {

    public List<User> getAllUser();//得到所有的用户

}

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE mapper

        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

    <mapper namespace="dao.UserDao">

      <select id="getAllUser" resultType="User">

          select * from user

      </select>

    </mapper>

import java.util.List;

import org.apache.ibatis.session.SqlSession;

import org.apache.ibatis.session.SqlSessionFactory;

import dao.UserDao;

import model.User;

import utils.SqlSessionFactorytest;

public class test {

public static void main(String[] args) {

	SqlSessionFactory sqlSessionFactory=SqlSessionFactorytest.getSqlSessionFactoryBuider();

	SqlSession sqlSession=sqlSessionFactory.openSession();

	System.out.println("SqlSession创造成功！！");
        //用SqlSession得到Mapper接口

	UserDao userDao=sqlSession.getMapper(UserDao.class);

	List<User> user=userDao.getAllUser();

	if(user!=null) {

		System.out.println("数据读取成功！！");

	}

	for(int x=0;x<user.size();x++) {

		User u=user.get(x);

		System.out.println(u.getId());

		System.out.println(u.getUsername());

		System.out.println(u.getPassword());

	}

}

}