1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
 3 <configuration>
 4     <!-- 将数据库连接信息简化到Java的属性文件中 -->
 5     <properties resource="jdbc.properties"></properties>
 6     
 7     <!-- 配置实体类的别名，配置实体类别名的目的是为了在引用实体类时可以使用实体类的别名来代替实体类，达到简写的目的  -->
 8     <typeAliases>
 9         <!-- com.mybatis2.entity包下的所有实体类配置别名，MyBatis默认的设置别名的方式就是去除类所在的包后的简单的类名 -->
10         <!-- 如com.mybatis2.entity.MyUser这个实体类的别名就会被设置成MyUser -->
11         <package name="com.mybatis2.entity"/>
12     </typeAliases>
13 
14     <!-- 配置开发模式, 添加数据库信息, 开启事务模式 -->
15     <environments default="development">
16         <environment id="development">
17             <transactionManager type="JDBC"></transactionManager>
18             <dataSource type="POOLED">
19                 <property name="driver" value="${mysql.driver}"/>
20                 <property name="url" value="${mysql.url}"/>
21                 <property name="username" value="${mysql.username}"/>
22                 <property name="password" value="${mysql.password}"/>
23             </dataSource>
24         </environment>
25     </environments>
26     
27     <mappers>
28         <mapper resource="com/mybatis2/mapper/MyUserMapper.xml"/>
29     </mappers>
30 </configuration>

1 create table MyUser (
2   id int primary key AUTO_INCREMENT,
3   name varchar(20),
4   password varchar(20)
5 )

 1 package com.mybatis2.entity;
 2 
 3 public class MyUser {
 4     /*
 5      * 1.MyUser.java对应表名
 6      * 2.id对应MyUser表中的主键
 7      * 3.username对应MyUser表中的用户名
 8      * 4.userpass对象MyUser表中的用户密码
 9      */
10     
11     private int id;
12     private String username;
13     private String userpass;
14     public int getId() {
15         return id;
16     }
17     public void setId(int id) {
18         this.id = id;
19     }
20     public String getUsername() {
21         return username;
22     }
23     public void setUsername(String username) {
24         this.username = username;
25     }
26     public String getUserpass() {
27         return userpass;
28     }
29     public void setUserpass(String userpass) {
30         this.userpass = userpass;
31     }
32     
33     @Override
34     public String toString() {
35         return "MyUser [id="+this.id+" username="+this.username+" userpass="+this.userpass+"]";
36     }
37 }

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 3 
 4 <!-- 给mapper指定一个唯一的namespace，namespace的值习惯上设置成包名+sql映射文件名 -->
 5 <mapper namespace="com.mybatis2.mapper.MyUserMapper">
 6 
 7     <!-- 根据用户的ID来查询 -->
 8     <!-- 使用占位符：#{}表示一个占位符 -->
 9     <select id="getMyUserById" resultType="MyUser" parameterType="java.lang.Integer">
10         select * from MyUser where id=#{id}
11     </select>
12 </mapper>

 1 package com.gxa.test;
 2 
 3 import java.io.IOException;
 4 import java.io.Reader;
 5 import java.util.List;
 6 
 7 import org.apache.ibatis.io.Resources;
 8 import org.apache.ibatis.session.SqlSession;
 9 import org.apache.ibatis.session.SqlSessionFactory;
10 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
11 import org.junit.Test;
12 
13 import com.gxa.pojo.MyUser;
14 import com.gxa.pojo.Team;
15 
16 public class Test01 {
17     /**
18      * 启动MyBatis去加载配置文件
19      * 1.java.io.Reader
20      * 2.Resources
21      * 3.SqlSessionFactory
22      */
23     private static Reader reader;
24     private static SqlSessionFactory sqlSessionFactory;
25     
26     static {
27         try {
28             reader = Resources.getResourceAsReader("config.xml");
29             sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
30         } catch (IOException e) {
31             e.printStackTrace();
32         }
33     }
34     
35     /**
36      * 1.初始化SqlSession, 执行SQL语句
37      * 2.告知程序读哪个映射文件
38      * 3.告知程序执行映射文件中哪个CRUD操作
39      */
40     @Test
41     public void m01() {
42         SqlSession sqlSession = sqlSessionFactory.openSession();
43         String sql = "com.gxa.mapper.MyUserMapper.getMyUser";
44         List<MyUser> list = sqlSession.selectList(sql);
45         System.out.println(list);
46         sqlSession.close();
47     }
48     
49 }