MyBatils课程一

<?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.yiibai.mybatis.models.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/yiibai" />
                <property name="username" value="root" />
                <property name="password" value="" />
                       </dataSource>
        </environment>
    </environments>

    <mappers>
         <mapper resource="com/yiibai/mybatis/models/User.xml" />
    </mappers>
</configuration>

package org.wangyi.com;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * 定义实体类
 * 
 * @author wangyi
 * @version 1.0 <br />
 *          <a href="www.baidu.com">百度一下</a>
 */
public class User {
    private int id;
    private String username;
    private Date birthday;
    private String sex;
    private String address;

    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 Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        String bd = format.format(this.birthday);
        String content = "User[ " + this.id + "," + this.username + ","
                + this.sex + "," + bd + "," + this.address + " ]";
        return content;
    }

}

<?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">
<!-- 为这个mapper指定一个唯一的namespace，namespace的值习惯上设置成包名+sql映射文件名，这样就能够保证namespace的值是唯一的 
    例如namespace="me.gacl.mapping.userMapper"就是me.gacl.mapping(包名)+userMapper(userMapper.xml文件去除后缀) -->
<mapper namespace="org.wangyi.mapping.userMapper">
    <!-- 在select标签中编写查询的SQL语句， 设置select标签的id属性为finduserByid，id属性值必须是唯一的，不能够重复 
        使用parameterType属性指明查询时使用的参数类型，resultType属性指明查询返回的结果集类型 resultType="org.wangyi.com.User"就表示将查询结果封装成一个User类的对象返回 
        User类就是users表所对应的实体类 -->
    <!-- 根据id查询得到一个user对象 -->
    <select id="finduserByid" parameterType="int" resultType="org.wangyi.com.User">
        select
        * from user where id=#{id}
    </select>
</mapper>

package org.wangy.first;

import java.io.FileInputStream;
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;
import org.junit.Test;
import org.wangyi.com.User;

/**
 * MyBatis的入门程序
 * 
 * @author wangyi
 * @version 1.0 <br />
 *          <a href="www.baidu.com">百度一下</a>
 * 
 */
public class MyBatisFirst {
    // 查询一条记录
    @Test
    public void findUserByid() throws IOException {
        // MyBatis的配置文件
        String resource = "SQLMapConfig.xml";
        // 得到SQLMapConfig.xml配置文件流
        String path = MyBatisFirst.class.getClassLoader().getResource(resource)
                .getPath();
        InputStream inputStream = new FileInputStream(path);
        // 使用MyBatis提供的Resources类加载mybatis的配置文件（它也加载关联的映射文件）
        // Reader reader = Resources.getResourceAsReader(resource)或者
        // InputStream inputStream = Resources.getResourceAsStream(resource);
        // 创建MyBatis的会话工厂
        SqlSessionFactory factory = new SqlSessionFactoryBuilder()
                .build(inputStream);
        // 得到会话sqlSession
        SqlSession sqlSession = factory.openSession();
        // 通过sqlSession操作数据库
        /**
         * 第一个参数：值=xxxMapper.xml文件中mapper标签的namespace属性的值+“.”+sql语句标签的id值，
         * 第二个参数：值=和映射文件所匹配的ResultType类型的参数
         */
        User user = sqlSession.selectOne(
                "org.wangyi.mapping.userMapper.finduserByid", 31);
        // 释放资源，不要忘记
        sqlSession.close();
        System.out.println(user);
    }

}