实战（一）：开发环境搭建

1.使用Myeclipse开发工具,配置好JAVA，等环境变量，下载Mysql连接时所需要的jar包，以及MyBatis的jar包。

2.建立一个web工程，将 mybatis-3.2.0-SNAPSHOT.jar，mysql-connector-java-5.1.22-bin.jar 拷贝到 web工程的lib目录.

3.在Mysql数据库里新建一个数据库。

新建一张表格

Create TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `userName` varchar(50) DEFAULT NULL,
  `userAge` int(11) DEFAULT NULL,
  `userAddress` varchar(200) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;

插入一行数据
Insert INTO `user` VALUES ('1', 'summer', '100', 'shanghai,pudong');

4.开始配置MyBatis

 在MyBatis 里面创建两个源码目录，分别为 src_user,test_src, 用如下方式建立,鼠标右键点击 JavaResource.

找不到JavaResource的，可以更换一个查看的视图点击Resource，在更换完视图后，将视图换回。

5.设置mybatis 配置文件:Configuration.xml, 在src_user目录下建立此文件，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>
<typeAliases>
<typeAlias alias="User" type="com.yihaomen.mybatis.model.User" />
</typeAliases>

<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/mybatis" />
<property name="username" value="root" />
<property name="password" value="123456" />
</dataSource>
</environment>
</environments>

<mappers>
<mapper resource="com/yihaomen/mybatis/model/User.xml" />
</mappers>
</configuration>

6. 建立与数据库对应的 java class,以及映射文件

在src_user下建立package:com.yihaomen.mybatis.model ,并在这个 package 下建立 User 类:

package com.yihaomen.mybatis.model;

public class User {
    
    private int id;
    private String userName;
    private String userAge;
    private String userAddress;
    
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getUserAge() {
        return userAge;
    }
    public void setUserAge(String userAge) {
        this.userAge = userAge;
    }
    public String getUserAddress() {
        return userAddress;
    }
    public void setUserAddress(String userAddress) {
        this.userAddress = userAddress;
    }

}

同时建立这个User 的映射文件 User.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="com.yihaomen.mybatis.models.UserMapper">
    <select id="selectUserByID" parameterType="int" resultType="User">
        select * from `user` where id = #{id}
    </select>
< /mapper>

 

7.配置好以后在test_src 源码目录下建立com.yihaomen.test这个package,并建立测试类Test:

package com.yihaomen.test;

import java.io.Reader;

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 com.yihaomen.mybatis.model.User;

public class Test {
    private static SqlSessionFactory sqlSessionFactory;
    private static Reader reader; 

    static{
        try{
            reader    = Resources.getResourceAsReader("Configuration.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        }catch(Exception e){
            e.printStackTrace();
        }
    }

    public static SqlSessionFactory getSession(){
        return sqlSessionFactory;
    }
    
    public static void main(String[] args) {
        SqlSession session = sqlSessionFactory.openSession();
        try {
        User user = (User) session.selectOne("com.yihaomen.mybatis.models.UserMapper.selectUserByID", 1);
        System.out.println(user.getUserAddress());
        System.out.println(user.getUserName());
        } finally {
        session.close();
        }
    }
}

运行测试类如果能查到结果，说明配置成功

 

整个层次结构如下：