<?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="dev">
  		<environment id="dev">
  			<transactionManager type="JDBC" />
  				<dataSource type="POOLED">
  				
  				<property name="driver" value="com.mysql.jdbc.Driver"/>
 				<property name="url" value="jdbc:mysql://localhost:3306/java505"/>
 				<property name="username" value="root"/>
 				<property name="password" value="szxy"/>
  				</dataSource>
  		</environment>
  		
  	</environments>
  	<mappers>
  	   <mapper resource="cn/bjsxt/mapper/usermapper.xml"/>
  	</mappers>
  </configuration>

 import java.io.Serializable;
    
    public class User implements Serializable{
    	private int id;
    	private String name;
    	private String password;
    	
    	public int getId() {
    		return id;
    	}
    	public void setId(int id) {
    		this.id = id;
    	}
    	public String getName() {
    		return name;
    	}
    	public void setName(String name) {
    		this.name = name;
    	}
    	public String getPassword() {
    		return password;
    	}
    	public void setPassword(String password) {
    		this.password = password;
    	}
    	public User(int id, String name, String password) {
    		super();
    		this.id = id;
    		this.name = name;
    		this.password = password;
    	}
    	public User() {
    		super();
    	}
    	@Override
    	public String toString() {
    		return "User [id=" + id + ", name=" + name + ", password=" + password + "]";
    	}
    	@Override
    	public int hashCode() {
    		final int prime = 31;
    		int result = 1;
    		result = prime * result + id;
    		result = prime * result + ((name == null) ? 0 : name.hashCode());
    		result = prime * result + ((password == null) ? 0 : password.hashCode());
    		return result;
    	}
    	@Override
    	public boolean equals(Object obj) {
    		if (this == obj)
    			return true;
    		if (obj == null)
    			return false;
    		if (getClass() != obj.getClass())
    			return false;
    		User other = (User) obj;
    		if (id != other.id)
    			return false;
    		if (name == null) {
    			if (other.name != null)
    				return false;
    		} else if (!name.equals(other.name))
    			return false;
    		if (password == null) {
    			if (other.password != null)
    				return false;
    		} else if (!password.equals(other.password))
    			return false;
    		return true;
    	}
    	
    	
    }

 <?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="cn.bjsxt.mapper.UserMapper">
    	<select id="selAll" resultType="cn.bjsxt.pojo.User">
    		select * from t_user
    	</select>  	
    	<select id="selOne" resultType="cn.bjsxt.pojo.User">
    		select * from t_user where id=1
    	</select>  
      </mapper>

package cn.bjsxt.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 cn.bjsxt.pojo.User;

public class TestSelect {
	@Test
	public void testSelectList() throws IOException {
		InputStream is = Resources.getResourceAsStream("mybatis-cfg.xml");
		SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);
		SqlSession session = factory.openSession();
		//1、selectList
		/**List<User> list = session.selectList("cn.bjsxt.mapper.UserMapper.selAll");
		for (User user : list) {
			System.out.println(user);
		}*/
		//2、selectOne
		/**User user = session.selectOne("cn.bjsxt.mapper.UserMapper.selOne");
		System.out.println(user);*/
		//3、selectMap
		Map<Integer, User> map = session.selectMap("cn.bjsxt.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();
	}
}