MyBitis(iBitis)系列随笔之一：MyBitis入门实例

 

 

 

MyBits前身是iBitis,相对于Hibernate而言,它是半自动化ORM框架。本着分享和学习的目的，笔者将陆续把学习笔记与代码贴出，希望对想学习mybitis的同窗们有所帮助。
       鉴于我的测试数据库是mysql，同仁们现在把mysql装好，然后准备好mysql驱动以及从官网上下载mybitis(http://code.google.com/p/mybatis/)。我下载的是最新的mybatis-3.2.2.zip。

   

      创建数据库test

       然后创建表t_user

DROP TABLE IF EXISTS `t_user`;
CREATE TABLE `t_user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) DEFAULT NULL,
  `pass` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=24 DEFAULT CHARSET=gbk;

INSERT INTO `t_user` VALUES ('1', 'ssssssssssssssss', 'ddsssssssdd');

     然后创建与表对应的Java bean对象

<span style="color:#000000;">package com.jefry;

public class User {
    private int id;
    private String name;
    private String pass;



    public String getPass() {
        return pass;
    }

    public void setPass(String pass) {
        this.pass = pass;
    }

    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;
    }

}</span>

       接下来，在classpath目录下面创建与配置mybatis-config.xml文件

       内容如下：

<?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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://127.0.0.1:3306/test"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
     <!--这个文件下面将创建-->
     <mapper resource="com/jefry/UserMapper.xml"/>
    </mappers>
</configuration>

        通过mybatis-config.xml中<mapper resource="com/jefry/UserMapper.xml"/>配置项，我们在包com.jefry下面创建文件UserMapper.xml
         内容如下：

<?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="User">
    <!--resultType 表示com.jefry.User这样一个实体对象 -->
    <select id="selectUser" parameterType="int" resultType="com.jefry.User">
        select * from t_user where id = #{id}
    </select>
</mapper>

     编写测试代码

package com.jefry;

import java.io.IOException;
import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

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

    public static void main(String[] args) throws IOException {
        // TODO Auto-generated method stub
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();
        try {
            //User.selectUser中User对应UserMapper.xml文件中标签<mapper namespace="User"> namespace的值
            //selectUser 对应UserMapper.xml文件中标签<select id="selectUser" parameterType="int" resultType="com.jefry.User">中id值
            User user = session.selectOne("User.selectUser", 1);
            System.out.println("user.getName()=" +  user.getName());
        } finally {
            session.close();
        }
    }

}

通过运行就可以结果：user.getName()=ssssssssssssssss