一、运行环境：
JDK1.8 + apache-tomcat-8.5.100
二、相关的jar包：
三、mybatis.xml配置文件
xml
<?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>
<package name="com.example.crud.model"/>
</typeAliases>
<environments default="dev">
<environment id="dev">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.cj.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://127.0.0.1:3306/demo?useSSL=false&serverTimezone=UTC"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<mappers>
<mappers>
<mapper resource="com/example/crud/dao/UserMapper.xml"/>
</mappers>
</mappers>
</configuration>四、修改myabtis配置文件：
办法一：
xml
<mappers>
<!-- 一次性扫描 com.example.crud.dao 下所有接口 + 同名 XML -->
<package name="com.example.crud.dao"/>
</mappers>办法二：文件通符（MyBatis 3.5.1+ 才支持
xml
<mappers>
<!-- 一次性加载 classpath 里所有匹配路径的 XML -->
<mapper url="classpath*:com/example/crud/dao/*Mapper.xml"/>
</mappers>办法三：Java 代码批量注册（纯 Servlet 项目可放在 Listener 里）
java
String packageName = "com.example.crud.dao";
Configuration cfg = sqlSessionFactory.getConfiguration();
ResolverUtil<Class<?>> resolver = new ResolverUtil<>();
resolver.find(new ResolverUtil.IsA(BaseMapper.class), packageName);
for (Class<?> mapper : resolver.getClasses()) {
cfg.addMapper(mapper);
}