According to the user guide i am able to use file path instead of resource:

// Using classpath relative resources
<mappers>
    <mapper resource="org/mybatis/builder/AuthorMapper.xml"/>
</mappers>

// Using url fully qualified paths
<mappers>
    <mapper url="file:///var/sqlmaps/AuthorMapper.xml"/>
</mappers>

in my project I'm trying to put my mapper xml "outside" the project and i'm doing this:

<mapper url="file://D:/Mappers/ComponentMapper1.xml" /> 

The output of my log4j console:

Error building SqlSession. 
The error may exist in file://D:/Mappers/ComponentMapper1.xml 
Cause: org.apache.ibatis.builder.BuilderException: Error parsing 
SQL Mapper Configuration. Cause: java.net.UnknownHostException: D