mybatis初步学习（一）

不要在傻逼的时候学习，更不要在傻逼的时候写代码，嘿嘿。写完这篇就睡，嘎嘎。

   1. mybatis是我目前见过最小的框架，跟hibernate相比，小的太多。最新版的3.2.2下载下来一看，源码都没有。只要先用的3.1.1。帮助文档也就是个简单的pdf。

   2.环境搭建：

添加2个必须的jar包，一个mybatis，一个mysql-connector。

       在src下编写配置文件mybatis-config.xml，如下：

<?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"></properties>  <environments default="development">  <environment id="development">    <transactionManager type="jdbc"></transactionManager>   <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="itat/zttc/shop/model/UserMapper.xml"/>  </mappers>    </configuration>

注：jdbc.properties中是关于数据库的的配置。同样在src下。

 3. 在User类所在的包下写对应的map配置文件，如下：

<?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="itat.zttc.shop.model.User">      <insert id="add" parameterType="itat.zttc.shop.model.User">    insert into t_user (username,password,nickname)  value(#{username},#{password},#{nickname})    </insert>    <update id="update" parameterType="itat.zttc.shop.model.User">    update t_user set username=#{username}, password=#{password},nickname=#{nickname} where id = #{id}    </update>    </mapper>

4.测试代码：

private static void testUpdate() {try {//1、创建配置文件(mybatis-config.xml)的输入流InputStream is = Resources.getResourceAsStream("mybatis-config.xml");//2、创建SQLSessionFactorySqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);//3、创建SQLSessioinSqlSession session = factory.openSession();//4、调用mapper文件插入数据（调用之前需要将mapper文件加入到mybatis-config.xml中）User u = new User();u.setNickname("孙悟空");u.setPassword("333");//u.setType(0);u.setUsername("wukong");u.setId(9);session.update("itat.zttc.shop.model.User.update",u);session.commit();session.close();} catch (IOException e) {e.printStackTrace();}}private static void testAdd() {try {//1、创建配置文件(mybatis-config.xml)的输入流InputStream is = Resources.getResourceAsStream("mybatis-config.xml");//2、创建SQLSessionFactorySqlSessionFactory factory = new SqlSessionFactoryBuilder().build(is);//3、创建SQLSessioinSqlSession session = factory.openSession();//4、调用mapper文件插入数据（调用之前需要将mapper文件加入到mybatis-config.xml中）User u = new User();u.setNickname("孙悟空");u.setPassword("123");//u.setType(0);u.setUsername("wukong");session.insert("itat.zttc.shop.model.User.add", u);session.commit();session.close();} catch (IOException e) {e.printStackTrace();}}