mybatis-config.xml文件的元素节点是有一定顺序的。
<?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">-->
<!--1.根节点-->
<configuration>
<!--2.properties外部指定的properties文件-->
<properties resource="database.properties"/>
<!--3.设置MyBatis运行的一些行为-->
<settings>
<setting name="logImpl" value="LOG4J"/>
<setting name="autoMappingBehavior value="NONE"/>
</settings>
<!--4.配置多套运行环境,将SQL语句映射到不同数据库上-->
<environments default="development">
<!--5.一套运行环境,需id,事务管理,数据源配置等-->
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<!--6.SQL映射文件-->
<mappers>
<mapper resource="smbms/dao/order/OrderMapper.xml"/>
</mappers>
</configuration>