specify relative path to file in web.xml

I'm having problem with setting the path to a file (using relative path)
my tomact structure is

Code:

---

tomcat-7
    - config
        - filterConfigs
    - webapps
        - exampleWebApp
            - META-INF
            - WEB-INF
                - web.xml
                - classes

---

in the web.xml

Code:

---

<filter>
  <filter-name>MY Filter</filter-name>
  <filter-class>com.filter.MyFilter</filter-class>
  <init-param>
    <param-name>keyStore</param-name>
    <param-value>../../config/filterConfigs/keystore.jks</param-value>
  </init-param>
</filter>

---

however, the filter cannot locate this file.
If I specified the absolute path, it will be pick it up.
so, how do i specify the relative path?

I'm not extremely familiar with Tomcat, but have seen something similar with other web containers in that the path cannot be found unless relative to the currently running JRE - so I'd say find where this is within Tomcat and place the file path relative to that directory.

wish i could do that. the folder contains Fedlet SSO configuration, keystore, etc.. and other stuff that multiple webappp uses.

I saw somewhere where someone use something like <param-value>home/tomcat/mydirectory</param-value>.
this is the ideal solution, but i'm not sure how to go about it.