You can use:
It gives you access to the objects you need, it is located in the jar:
As I am looking into the same things, I am curious to know which reporting solution you are integrating.
You can try this.
JbossActionRequest acReq = new JbossActionRequest(actionRequest); Here the actionRequest is of type ActionRequest HttpRequest httpReq = acReq.getControllerContext().getServerInvocation().getServerContext().getClientRequest(); Similarly you can get handle to HttpServletResponse. If can get the handle from RenderRequest as well. Instead of ActionRequest just use RenderRequest in the above code.
Alternatively if you are using a Portlet Bridge like Struts or JSF, You can even directly get the handle from the available interceptors provided by the portlet bridge. In that case it would be an implicit object under the portlet. These are injected to portlets by the bridge.