首先不管如何記得在配置檔案裡寫入對映檔案（<mapper>標籤）

實體類參考

public class Person {

 private Integer pId;
 private String pName;//當和表裡的列名不一致的時候，查詢語句應該起別名
 //p_Name(原表裡的列名） pname別名
 private String email;
 public Person() {
 }

介面

package com.yiki.Dao;

import com.yiki.Entity.Person;
import org.apache.ibatis.annotations.Param;

public interface PersonMapperPlus {

 public Person getPersonById(Integer id);

}
 

mapper

<?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.yiki.Dao.PersonMapperPlus">

    <!--對某個bean自定義對映規則
    【type】寫全類名和別名都可以（前提是寫了別名）
    【id】這個規則的唯一標識-->
    <resultMap id="myRule" type="com.yiki.Entity.Person">
        <!--指定主鍵列，使得框架優化規則
        【column】指定列
        【property】制定對應bean的屬性值-->
        <id column="pId" property="pId"/>
        <!--指定普通列-->
        <result column="pName" property="p_Name"/>
        <result column="email" property="email"/>
        <!--其他列名不指定也可以自動封裝，但是還是最好都寫上-->
    </resultMap>

    <!--【resultMap】自定義結果集對映規則（不能和resultType混用-->
    <select id="getPersonById" resultMap="myRule">
        select * from Person where pid=#{pId}
    </select>

</mapper>


 

測試類

package com.yiki.Test;

import com.yiki.Dao.PersonMapper;
import com.yiki.Dao.PersonMapperAnno;
import com.yiki.Dao.PersonMapperPlus;
import com.yiki.Entity.Person;
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.apache.log4j.Logger;
import org.junit.Test;

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

public class TestPlus {
 private String resource;
 private InputStream inputStream;
 private SqlSessionFactory sqlSessionFactory;
 private SqlSession sqlSession;
 private PersonMapperPlus mapper;
 private Logger log;

 public void start() throws IOException {
  resource = "mybatis.xml";//根據全域性配置檔案
  inputStream = Resources.getResourceAsStream(resource);
  sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
  sqlSession = sqlSessionFactory.openSession(true);
  mapper = sqlSession.getMapper(PersonMapperPlus.class);
  log = Logger.getLogger(this.getClass());
 }

 @Test
 public void test1() throws IOException {
  start();
  Person person = mapper.getPersonById(1);
  System.out.println(person);


  sqlSession.close();
 }


}