【Mybatis】环境搭建

<?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>
    <!--配置环境-->
    <environments default="mysql">
        <environment id="mysql">
            <!--配置事务的类型-->
            <transactionManager type="JDBC"></transactionManager>
            <!--配置数据源（连接池）-->
            <dataSource type="POOLED">
                <!--配置连接数据库的4个基本信息-->
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
                <property name="username" value="root"/>
                <property name="password" value=""/>
            </dataSource>
        </environment>
    </environments>
    <!--1.指定映射文件的位置，映射配置文件指的是每个dao独立的配置文件
             <mapper resources="com.ysong.dao.IUserDao.xml"></mapper>
        2.如果这里用的是注解，用class属性指定被注解的dao全限定名
            <mapper class="com.ysong.dao.IUserDao"></mapper>
    -->
    <mappers>
        <mapper class="com.ysong.dao.IUserDao"></mapper>
    </mappers>
</configuration>

package com.ysong.dao;

import com.ysong.domain.User;
import org.apache.ibatis.annotations.Select;

import java.util.List;

public interface IUserDao {
    @Select("select * from user")
    List<User> findAll();
    
}

/**
 * Copyright (C), 2015-2019, XXX有限公司
 * FileName: MyBatisTest
 * Author:   Administrator
 * Date:     2019/5/29 19:20
 * Description:
 **/
package com.ysong.test;

import com.ysong.dao.IUserDao;
import com.ysong.domain.User;
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 java.io.InputStream;
import java.util.List;

public class MyBatisTest {
    public static void main(String[] args) throws Exception {
        //1.读取配置文件
        InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
        //2.创建sqlSessionFactory工厂
        SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
        SqlSessionFactory factory = builder.build(in);
        //3.使用工厂生产sqlSession对象
        SqlSession session = factory.openSession();
        //4.使用sqlsession创建Dao接口的代理对象
        IUserDao userDao = session.getMapper(IUserDao.class);
        //5.使用代理对象执行方法
        List<User> users = userDao.findAll();
        for (User user : users) {
            System.out.println(user);
        }
        //6.释放资源
        session.close();
        in.close();
    }
}