java ee - Issue with 'context.setResponseContentLength(fileSize)' metthod in JSF -

java ee - Issue with 'context.setResponseContentLength(fileSize)' metthod in JSF -

i using 'jsf-api-2.1.2.jar' file build web app jsf , there have created object of externalcontext. usimhg object access 'responsereset()', 'setresponsecontenttype(string)'and setresponsecontentlength(int) showing these method not exist. have checked 'externalcontext.class' file , saw methods exist in class not sure why showing them undefine methods. running project on jboss 5.1 server. can please assist me on this. in advance!

jsf java-ee xhtml jboss5.x