逛奔的蝸牛

簡介: 

iBatis更名為MyBatis，作出了些修改. 如以前使用SqlMapClient進行數據庫操作，現在使用SqlSession.

jar包

普通的javaBean: domain.User

與bean對應的SQL映射文件: maps/User.xml

MyBatis需要的配置文件: mybatis.cfg.xml

1. 需要的jar包: mybatis-3.0.2.jar (只有此一個是必須的，比iBatis清楚多了).

2. 類User:

package domain;

public class User {

    private int id;

    private String name;

    public User() {}

    public User(String name) { this(0, name); }

    public User(int id, String name) {

        this.id = id;

        this.name = name;

    }

    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; }

    @Override

    public String toString() { return "ID: " + id + ", Name: " + name; }

}

3. User.xml映射文件:

<?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">

    <select id="selectUser" parameterType="int" resultType="User"><![CDATA[

        select * from user where id = #{id}

    ]]></select>

</mapper>

4. MyBatis需要的配置文件:

<?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="domain.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://localhost:3306/test?useUnicode=true&amp;characterEncoding=UTF-8" />

                <property name="username" value="root" />

                <property name="password" value="" />

            </dataSource>

        </environment>

    </environments>

    

    <mappers>

        <mapper resource="maps/User.xml" />

    </mappers>

</configuration>

5. 使用MyBatis訪問數據庫:

import java.io.IOException;

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 domain.User;

public class Test {

    public static void main(String[] args) throws IOException {

        String resource = "mybatis.cfg.xml";

        Reader reader = Resources.getResourceAsReader(resource);

        SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(reader);

        

        SqlSession session = ssf.openSession();

        

        try {

            User user = (User) session.selectOne("selectUser", "3");

            System.out.println(user);

        } catch (Exception e) {

            e.printStackTrace();

        } finally {

            session.close();

        }

    }

}