在 MyBatis入门（一） 的基础之上编写接口
将接口和Mapper文件进行绑定，会为接口创建一个代理对象，代理对象去执行增删改查
（1）编写接口
public interface EmpDao {
public Emp getEmp(Integer id);
}
（2）修改Mapper文件
<?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.eu.dao.EmpDao">
<select id="getEmp" resultType="com.eu.pojo.Emp">
select id,last_name lastName,gender,email from Emp where id = #{id}
</select>
</mapper>
（3）编写测试
@Test
public void testMapper02() throws IOException {
//1.获取SqlSessionFactory对象
String resource = "conf/mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//2.获取SqlSession对象
SqlSession session = sqlSessionFactory.openSession();
try {
//3.获取接口的实现类对象
EmpDao empDao = session.getMapper(EmpDao.class);
Emp emp = empDao.getEmp(1);
System.out.println(emp);
} finally {
session.close();
}
}
（4）运行结果
DEBUG 04-14 23:01:47,690 ==> Preparing: select id,last_name lastName,gender,email from Emp where id = ? (BaseJdbcLogger.java:145)
DEBUG 04-14 23:01:47,801 ==> Parameters: 1(Integer) (BaseJdbcLogger.java:145)
DEBUG 04-14 23:01:47,842 <== Total: 1 (BaseJdbcLogger.java:145)
Emp [id=1, lastName=张三, geder=null, email=we.com]