mybatis连接mysql的实现过程

<dependencies>
    <!--junit单元测试坐标-->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <!--mysql连接数据库的依赖坐标坐标-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.11</version>
    </dependency>

    <!--导入mybatis坐标-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.5</version>
    </dependency>

    <!--导入druid连接池-->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.1.24</version>
    </dependency>

    <!--导入dbutils坐标-->
    <dependency>
      <groupId>commons-dbutils</groupId>
      <artifactId>commons-dbutils</artifactId>
      <version>1.6</version>
    </dependency>


  </dependencies>

<?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">
      <!--连接配置->
        <property name="driver" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
 	<!--mappper映射路径-->
    <mapper resource="UserMapper.xml"/>
  </mappers>
</configuration>

<?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="test">
  <select id="selectAll" resultType="model.User">
    select * from Blog where id = #{id}
  </select>
 
</mapper>

package mybatis;
import model.User;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class MybatisTest {

    @Test
    public void method() throws IOException {     //单元测试不能要static
        //mybatis框架都在xml配置文件中加载配置文件
        //从 XML 文件中构建 SqlSessionFactory 的实例
        String resource = "mybatis-config.xml";
        InputStream inputStream = null;

        inputStream = Resources.getResourceAsStream(resource);

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

        //从 SqlSessionFactory 中获取 SqlSession
        SqlSession session = sqlSessionFactory.openSession();


        //执行sql
        List<User> users=session.selectList("test.selectAll"，2);

        System.out.println(users);

        //释放资源
        session.close();

    }
}