目录
一：MyBatis核⼼配置⽂件详解
<?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="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/po
wernode"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="CarMapper.xml"/>
</mappers>
</configuration>1. Mybatis核心配置文件之多环境
<?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>
<!-- 默认获取的是mybatis数据库-->
<environments default="mybatisDB">
<!--连接的是mybatis数据库-->
<environment id="mybatisDB">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<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="123"/>
</dataSource>
</environment>
<!--连接的是bjpowernode数据库-->
<environment id="bjpowernodeDB">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/bjpowernode"/>
<property name="username" value="root"/>
<property name="password" value="123"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--关联CarMapper.xml配置文件-->
<mapper resource="CarMapper.xml"/>
</mappers>
</configuration><?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="car">
<insert id="insertCar">
insert into t_car values(null,'8888','特斯拉',30.0,'2000-11-11','燃油车')
</insert>
</mapper>package com.bjpowernode.mybatis.test;
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;
/**
* @Author：朗朗乾坤
* @Package：com.bjpowernode.mybatis.test
* @Project：mybatis
* @name：ConfigurationTest
* @Date：2022/12/30 20:15
*/
public class ConfigurationTest {
@Test
public void testEnvironment() throws Exception{
SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
// 使用默认的
SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(Resources.getResourceAsStream("mybatis-config.xml"));
// 自己指定连接数据库的对象
SqlSessionFactory sqlSessionFactory = sqlSessionFactoryBuilder.build(Resources.getResourceAsStream("mybatis-config.xml"), "bjpowernodeDB");
SqlSession sqlSession = sqlSessionFactory.openSession();
// 执行sql
int count = sqlSession.insert("car.insertCar");
System.out.println(count);
sqlSession.commit();
sqlSession.close();
}
}
2. Mybatis事务管理器
<transactionManager type="JDBC"/>3. 对数据源的深度剖析
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/bjpowernode"/>
<property name="username" value="root"/>
<property name="password" value="123"/>
<!--连接池中最多正在使用的连接对象的数量上限，默认是10-->
<property name="poolMaximumActiveConnections" value="10" />
<!--最多的空闲数量-->
<property name="poolMaximumIdleConnections" value="5" />
<!--强行让让某个连接空闲，超时时间的设置-->
<property name="poolMaximumCheckoutTime" value="100000" />
<!--每隔2秒打印日志，并且尝试获取连接对象-->
<property name="poolTimeToWait" value="2000" />
</dataSource>4. properties和mapper标签的配置和使用
<?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>
<!-- 单独抽取出来连接数据库的代码-->
<properties>
<property name="jdbc.driver" value="com.mysql.jdbc.Driver" />
<property name="jdbc.url" value="jdbc:mysql://localhost:3306/mybatis" />
<property name="jdbc.username" value="root" />
<property name="jdbc.password" value="123" />
</properties>
<settings>
<setting name="logImpl" value="SLF4J"/>
</settings>
<!-- 默认获取的是mybatis数据库-->
<environments default="mybatisDB">
<!--连接的是mybatis数据库-->
<environment id="mybatisDB">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--关联CarMapper.xml配置文件-->
<mapper resource="CarMapper.xml"/>
</mappers>
</configuration>jdbc.properties配置文件
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis
jdbc.username=root
jdbc.password=123使用resource引入配置文件
<?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>
<!--resource一定是从类路径下开始查找资源-->
<properties resource="jdbc.properties" />
<settings>
<setting name="logImpl" value="SLF4J"/>
</settings>
<!-- 默认获取的是mybatis数据库-->
<environments default="mybatisDB">
<!--连接的是mybatis数据库-->
<environment id="mybatisDB">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driver}"/>
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--关联CarMapper.xml配置文件-->
<mapper resource="CarMapper.xml"/>
</mappers>
</configuration><!--从绝对路径下加载-->
<properties url="file:///d:/jdbc.properties" />
