MyBatis试用

http://dcrpp./blog/674072
今天刚听说iBATIS改名为MyBatis，实际上就是iBATIS 3.0.1。以前都是用hibernate或者JPA，同时听说iBATIS 3与iBATIS 2 相比，变化挺大的，于是今天花了点时间学习了一下，做了个小例子。 

准备工作：建立相应的数据库，表，添加一条记录用于测试。
第一步当然是建立项目，导入jar包，导入mybatis-3.0.1.jar，和mysql的jdbc驱动。

 第二步 新建一个类User，包含主键，用户名，密码等属性 

package cn.dcr.mybatis.entity;

public class User {
    private Long id;
    private String userName;
    private String password;
    private int age;

    public Long getId() {
        return id;
    }

    public void setId(Long 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 int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

}

 第三步，写sql映射的xml文件

 

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//ibatis.//DTD Mapper 3.0//EN"
"http://ibatis./dtd/ibatis-3-mapper.dtd">

<mapper namespace="cn.dcr.mybatis.entity.UserMapper">
    <select id="selectOne" parameterType="long" resultType="cn.dcr.mybatis.entity.User">
        select * from user where id = #{id}
    </select>
</mapper>

 

 第四步，写MyBatis配置文件，configuration.xml

 

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
    PUBLIC "-////DTD Config 3.0//EN"
    "http:///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://localhost:3306/test"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="cn/dcr/mybatis/entity/User.xml"/>
    </mappers>
</configuration>

 

第五步，编写Util类，用于初始化SqlSessionFactory

 

package cn.dcr.mybatis.util;

import java.io.IOException;
import java.io.Reader;

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

public class Util {

    private static SqlSessionFactory sqlSessionFactory = null;

    static {
        String resource = "configuration.xml";

        Reader reader = null;
        try {
            reader = Resources.getResourceAsReader(resource);
        } catch (IOException e) {
            e.printStackTrace();
        }

        sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
    }

    public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }
}

 

 

第六步，编写Dao类，用于封装增删改查等操作（为简单起见，这个类只有一个根据id查询出对应的User对象的方法）

 

package cn.dcr.mybatis.dao;

import org.apache.ibatis.session.SqlSession;

import cn.dcr.mybatis.entity.User;
import cn.dcr.mybatis.util.Util;

public class UserDao {
    public User query(Long id){
        SqlSession session = Util.getSqlSessionFactory().openSession();
        User user = null;
        try{
             user = (User)session.selectOne("cn.dcr.mybatis.entity.UserMapper.selectOne", id);
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            session.close();
        }
        return user;
    }
}

 

第七步，编写测试类

 

package cn.dcr.mybatis.test;

import cn.dcr.mybatis.dao.UserDao;
import cn.dcr.mybatis.entity.User;

public class UserTest {
    public static void main(String[] args){
        UserDao userDao = new UserDao();
        User user = userDao.query(1L);

        System.out.println(user.getId());
        System.out.println(user.getUserName());
        System.out.println(user.getPassword());
        System.out.println(user.getAge());
    }
}

 

 

运行一下，能够成功查询出对应的记录。

 

先到这，等有功夫在研究一下详细用法。

 

比较详细了，不上传源码了。