如何通过ehcache for mybatis使用环境配置文件？

<dependency>
    <groupId>org.mybatis.caches</groupId>
    <artifactId>mybatis-ehcache</artifactId>
    <version>1.2.3</version>
</dependency>
<dependency>
    <groupId>net.sf.ehcache</groupId>
    <artifactId>ehcache</artifactId>
    <version>2.10.6</version>
</dependency>

<ehcache>
    <cache name="exampleCache"
           maxElementsInMemory="100"
           eternal="false"
           timeToIdleSeconds="120"
           timeToLiveSeconds="120"
           overflowToDisk="false"/>
</ehcache>

<configuration>
    <settings>
        <setting name="cacheEnabled" value="true"/>
        <setting name="localCacheScope" value="SESSION"/>
        <setting name="cacheImpl" value="org.mybatis.caches.ehcache.EhcacheCache"/>
        <setting name="ehcacheConfiguration" value="classpath:ehcache.xml"/>
    </settings>
    ...
</configuration>

@CacheNamespace(implementation = org.mybatis.caches.ehcache.EhcacheCache.class)
public interface UserMapper {
    @Select("SELECT * FROM users WHERE id = #{id}")
    User getUserById(int id);
}