入门案例：
在IDEA中新建了一个普通的java项目，加入jar包,工程结构如图。

图片.png

log4j.properties（在控制台打印日志，方便查看）

# Global logging configuration

log4j.rootLogger=DEBUG, stdout

# Console output...

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

SqlMapConfig.xml（mybatis全局配置文件）

<?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">
            <!-- 使用jdbc事务管理，事务控制由mybatis-->
            <transactionManager type="JDBC"/>
            <!-- 数据库连接池,由mybatis管理-->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql:///mybatis001"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
</configuration>

ItemsMapper.xml（映射文件，sql语句）

<?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 命名空间，作用就是对sql进行分类化管理,理解为sql隔离
 注意：使用mapper代理方法开发，namespace有特殊重要的作用
 -->
<mapper namespace="mapper.ItemsMapper">

    <!-- public List<Items> queryItemsById(Integer id);-->
    <select id="queryItemsById" parameterType="int" resultType="po.Items">
        SELECT * FROM items WHERE id = #{id}
    </select>
</mapper>

在sqlMapConfig.xml中加载User.xml

 <mappers>
        <mapper resource="mapper/ItemsMapper.xml"/>
 </mappers>

程序代码

Items.java

package po;

/**
 * Created by admin on 2017/7/1.
 */
public class Items {
    private int id;
    private String name;
    private double price;
    private String detail;

    @Override
    public String toString() {
        return "Items{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", price=" + price +
                ", detail='" + detail + '\'' +
                '}';
    }
//get/set方法省略
}

测试类Test.jav

package test;

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 po.Items;

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

/**
 * Created by admin on 2017/7/1.
 */
public class Test {


    @org.junit.Test
    public void test01() throws IOException {

        String path = "SqlMapConfig.xml";
        InputStream inputStream = Resources.getResourceAsStream(path);
        //创建会话工厂，传入mybatis配置文件的信息
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);

        // 通过工厂得到SqlSession
        SqlSession sqlSession = sqlSessionFactory.openSession();
        Items list = sqlSession.selectOne("mapper.ItemsMapper.queryItemsById",1);
        System.out.println(list);
        sqlSession.close();

    }
}

查询结果

图片.png