public class User {

	private  String id;//用户编号

    private String username;//用户名

	private String password;//用户密码

    public String getId() {

		return id;

	}

	public void setId(String id) {

		this.id = id;

	}

	public String getUsername() {

		return username;

	}

	public void setUsername(String username) {

		this.username = username;

	}

	public String getPassword() {

		return password;

	}

	public void setPassword(String password) {

		this.password = password;

	}

}

public interface UserDao {

    public List<User> getAllUser();//得到所有的用户

}

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE mapper

        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"

        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

    <mapper namespace="dao.UserDao">

      <select id="getAllUser" resultType="User">

          select * from user_inf

      </select>

    </mapper>

public class SqlSessionFactorytest {

	//定义参数

	public static SqlSessionFactory sqlSessionFactory=null;

	//定义配置文件

	public static String resource="mybatis-config.xml";

	public static InputStream inputStream;

//构建SesseionFactory

	public static SqlSessionFactory getSqlSessionFactoryBuider() {

		try {

			//读取配置文件

			inputStream=Resources.getResourceAsStream(resource);

			System.out.println("配置文件加载成功！！");

			//SqlSessionFactoryBuilder通过输入流的相关配置得到sqlSessionFactory

		}catch(IOException e) {

			e.printStackTrace();

		}

		sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);

		System.out.println("sqlSessionFactory创造成功！！");

		return sqlSessionFactory;

	}

}

public class test {

       public static void main(String[] args) {
        //有工具类获得SqlSessionFactory

	SqlSessionFactory sqlSessionFactory=SqlSessionFactorytest.getSqlSessionFactoryBuider();

	//由SqlSessionFactoty获得SqlSession
        SqlSession sqlSession=sqlSessionFactory.openSession();
        //获得Mapper接口

	UserDao userDao=sqlSession.getMapper(UserDao.class);

	List<User> user=userDao.getAllUser();

	for(int x=0;x<user.size();x++) {

		User u=user.get(x);

		System.out.println(u.getId());

		System.out.println(u.getUsername());

		System.out.println(u.getPassword());

	}

}

}