数据库脚本(注意测试时先add-->load-->update-->delete-->list)

UserMapper版

-- --------------------------------------------------------
-- 主机:                           127.0.0.1
-- 服务器版本:                        5.5.36-MariaDB - mariadb.org binary distribution
-- 服务器操作系统:                      Win32
-- HeidiSQL 版本:                  8.0.0.4396
-- --------------------------------------------------------

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET NAMES utf8 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE=‘NO_AUTO_VALUE_ON_ZERO‘ */;

-- 导出 mybatis 的数据库结构
CREATE DATABASE IF NOT EXISTS `mybatis` /*!40100 DEFAULT CHARACTER SET utf8 */;
USE `mybatis`;

-- 导出  表 mybatis.t_user 结构
CREATE TABLE IF NOT EXISTS `t_user` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `username` varchar(50) DEFAULT NULL,
  `password` varchar(50) DEFAULT NULL,
  `nickname` varchar(50) DEFAULT NULL,
  `type` tinyint(4) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

mybatis-config.xml

<?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>
    <properties resource="jdbc.properties" />

    <typeAliases>
        <!--把edu.hhxy.btaisUser类都自动映射为User -->
        <typeAlias type="edu.hhxy.btais.User" alias="User" /> 
        <!-- 把edu.hhxy.btais所有类都自动映射 -->
        <package name="edu.hhxy.btais" />
    </typeAliases>
    <!-- 在properties之后加上typeAliases -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <!-- 配置mybatis的pooled的数据源 -->
            <dataSource type="POOLED">
                <property name="driver" value="${driver}" />
                <property name="url" value="${url}" />
                <property name="username" value="${username}" />
                <property name="password" value="${password}" />
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="edu/hhxy/btais/UserMapper.xml" />
    </mappers>
</configuration>

UserMapper.java

package edu.hhxy.btais.mapper;

import java.util.List;

import edu.hhxy.btais.User;

public interface UserMapper {
    /*
     * 基于annotation的方法知道就行了
     */
    // @Insert("insert into t_user(username,password,nickname,type) value(#{username},#{password},#{nickname},#{type})")
    public void add(User user);

    public void insert(User user);

    public void update(User user);

    public void delete(User user);

    public User load(Integer integer);

    public List<User> list();

}

UserMapper.xml

<?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="edu.hhxy.btais.mapper.UserMapper">
    <insert id="add" parameterType="User">
        insert into t_user
        (username,password,nickname,type)
        value(#{username},#{password},#{nickname},#{type})
    </insert>
    <update id="update" parameterType="User">
        update t_user set
        password=#{password},nickname=#{nickname},type=#{type} where id=#{id}
    </update>
    <delete id="delete" parameterType="int">
        delete from t_user where
        id=#{id}
    </delete>
    <select id="load" parameterType="int" resultType="User">
        select * from
        t_user where id=#{id}
    </select>

    <select id="list" resultType="User">
        select * from t_user
    </select>
</mapper>

TestMybatisByMapper.java

package edu.hhxy.btais;

import java.util.List;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import edu.hhxy.btais.mapper.UserMapper;
import edu.hhxy.btais.util.MyBatisUtil;
public class TestMybatisByMapper {
    @Test
    public void test() {
        addTest();
　　　　 loadTest();
        updateTest();
　　　　 listTest();
        deleteTest();
    }
    @Test
    public void addTest() {
        SqlSession session = null;
        try {
            session = MyBatisUtil.createSeqSession();
            User u = new User();
            u.setNickname("猪八戒");
            u.setPassword("123");
            u.setType(1);
            u.setUsername("bajie");
            session.getMapper(UserMapper.class).add(u);
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            MyBatisUtil.closeSeqSession(session);
        }
    }

    @Test
    public void updateTest() {
        SqlSession session = null;
        try {
            session = MyBatisUtil.createSeqSession();
            User u = new User();
            u.setNickname("齐天大圣孙悟空");
            u.setPassword("123");
            u.setType(0);
            u.setId(1);
            u.setUsername("wukong");
            session.getMapper(UserMapper.class).update(u);
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            MyBatisUtil.closeSeqSession(session);
        }
    }

    @Test
    public void deleteTest() {
        SqlSession session = null;
        try {
            session = MyBatisUtil.createSeqSession();
            User u = new User();
            u.setId(1);
            session.getMapper(UserMapper.class).delete(u);
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            MyBatisUtil.closeSeqSession(session);
        }
    }

    @Test
    public void loadTest() {
        SqlSession session = null;
        try {
            session = MyBatisUtil.createSeqSession();
            User u = (User) session.getMapper(UserMapper.class).load(3);
            System.out.println(u.toString());
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            MyBatisUtil.closeSeqSession(session);
        }
    }

    @Test
    public void listTest() {
        SqlSession session = null;
        try {
            session = MyBatisUtil.createSeqSession();
            List<User> us =session.getMapper(UserMapper.class).list();
            System.out.println(us.size());
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            MyBatisUtil.closeSeqSession(session);
        }
    }
}

运行前：

junit: