idea设置自定义的mybatis的Mapper.xml文件

自定义创建模板：

File->setting->Editor->File and Code Templates

选择 Files ， 点击 + 新建模板
Name MyBatisMapper
Extension xml
勾选 Enable live Templates

内容参考mybatis官网

<?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="org.mybatis.example.BlogMapper">
  <select id="selectBlog" resultType="Blog">
    select * from Blog where id = #{id}
  </select>
</mapper>

点击 apply ok