Mybatis 环境搭建

Mybatis简介：开源免费框架，原名iBatis。

• 数据访问层框架
• 底层是对JDBC的封装

 

一、mysql时区报错

• show variables like '%time_zone';
• set global time_zone='+8:00';

 

二、mybatis需要的jar包

• mybatis.jar
• mysql-connector-java.jar

 

三、src/mybaits.xml（配置数据库连接）

<?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>

       <environments default="default">

              <environment id="default">

                     <transactionManager type="JDBC"></transactionManager>

                     <dataSource type="POOLED">

                           <property name="driver" value="com.mysql.cj.jdbc.Driver"/>

                           <property name="url" value="jdbc:mysql://localhost:3306/test"/>

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

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

                     </dataSource>

              </environment>

       </environments>

       <mappers>

              <mapper resource="test.xml"/>

       </mappers>

</configuration>

 

四、test.xml（配置sql语句，理解成DAO的实现类）

<?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="a">

       <select id="sel" resultType="a.b.T1">

              select * from t1

       </select>

</mapper>

 

五、Main.java

package a.b;

 

import java.io.IOException;

import java.io.InputStream;

import java.util.List;

 

import org.apache.ibatis.io.Resources;

import org.apache.ibatis.session.SqlSession;

import org.apache.ibatis.session.SqlSessionFactory;

import org.apache.ibatis.session.SqlSessionFactoryBuilder;

 

public class Main {

 

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

        InputStream is=Resources.getResourceAsStream("mybatis.xml");

        SqlSessionFactory sf=new SqlSessionFactoryBuilder().build(is);

        SqlSession ss=sf.openSession();

        List<T1> list=ss.selectList("a.sel");

        for(T1 data:list) {

            System.out.println(data.toString());

        }

        

        ss.close();

    }

 

}