<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><properties resource="db.properties"/><settings><!-- 设置MyBatis使用log4j日志支持 -->  <setting name="logImpl" value="LOG4J"/> </settings><!-- 用于指定使用哪个环境 default: 用于指定使用的环境id --><environments default="development"><!-- 用于配置开发环境     id: 环境的唯一识别码    --><environment id="development"><!-- 事务管理器 type: 用于设置mybatis采用什么方式管理事务   JDBC表示采用和JDBC一样的事务管理方式   --><transactionManager type="JDBC"></transactionManager><!--数据源/连接池, 用于配置连接池和数据库连接的参数 type: 用于设置mybatis是否采用连接池技术      POOLED表示MyBatis采用连接池技术  --><dataSource type="POOLED"><property name="driver" value="${jdbc.driver}" /><property name="url" value="${jdbc.url}" /><property name="username" value="${jdbc.username}" /><property name="password" value="${jdbc.password}" />  </dataSource></environment></environments><!-- 扫描mapper文件 --> <mappers><mapper resource="com/sxt/mapper/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">
<!--   namespace: 命名空间, 可以随意定义, 一般情况下要写全限定路径  MyBatis管理SQL语句是通过namespace+id来定位的  --><mapper namespace="com.bjsxt.mapper.UserMapper"> <!--    select标签用于编写查询语句   id: sql语句的唯一标识, 类比为方法名   resultType: 用于设定返回结果的类型(全限定路径)    如果返回结果是集合, 要写集合泛型的类型   -->
<select id="selAll" resultType="com.bjsxt.pojo.User">select * from t_user
</select>
</mapper>

package com.sxt.test;import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.Map;
import java.util.Set;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 com.sxt.pojo.User;public class TsetSelectList{@Testpublic void testSelectList() throws IOException {InputStream is = Resources.getResourceAsStream("mybatis.xml");SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);SqlSession session = factory.openSession();List<User> list = session.selectList("com.sxt.mapper.UserMapper.selAll");System.out.println(list);for (User user : list) {System.out.println(user);}session.close();}@Testpublic void testSelectOne() throws IOException {InputStream is = Resources.getResourceAsStream("mybatis.xml");SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);SqlSession session = factory.openSession();User user = session.selectOne("com.sxt.mapper.UserMapper.selOne");System.out.println(user);session.close();}@Testpublic void testSelectMap() throws IOException {InputStream is = Resources.getResourceAsStream("mybatis.xml");SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);SqlSession session = factory.openSession();Map<Integer, User> map = session.selectMap("com.sxt.mapper.UserMapper.selAll", "id");System.out.println(map);Set<Integer> set = map.keySet();for (Integer k : set) {System.out.println(map.get(k));}session.close();}
}