Can you tell me what are the parameters to be set in the method
WebRequest.setURL(java.lang.String theServerName, java.lang.String theContextPath, java.lang.String theServletPath, java.lang.String thePathInfo, java.lang.String theQueryString ) 

taking an example that I'm using 
cactus.servletRedirectorURL = http://localhost:8180/test/ServletRedirector/

in my cactus.properties file

-Suresh