Url rewrite issue not getting current session (getPrincipal()) for redirected url

I have rewrited url f开发者_开发知识库rom: http://www.xyz.com/Sample/showSamples-ASA21DS to: http://www.xyz.com/Sample/showSamples.do?sampleId=ASA21DS

using urlRewrite.xml

<urlrewrite>

<rule>
    <from>^/http://www.xyz.com/Sample/showSamples-ASA21DS</from>
    <to>http://www.xyz.com/Sample/showSamples.do?sampleId=ASA21DS</to>
</rule>
</urlrewrite>

But, I dont get current session for this new url.. For this,

SecurityContextHolder.getContext().getAuthentication().getPrincipal()

i m getting null

Check to make sure the new request is still going through the Spring Security filters. This question is actually on the official FAQ page: http://static.springsource.org/spring-security/site/faq/faq.html#faq-no-filters-no-context