If your current request is coming from an "inside the app-server" forward or include, the app-server is expected to preserve request information as request attributes. The specific attributes, and what they contain, depends on whether you're doing a forward or an include.
For <jsp:include>
, the original parent URL will be returned by request.getRequestURL()
, and information about the included page will be found in the following request attributes:
javax.servlet.include.request_uri
javax.servlet.include.context_path
javax.servlet.include.servlet_path
javax.servlet.include.path_info
javax.servlet.include.query_string
For <jsp:forward>
, the new URL will be returned by request.getRequestURL()
, and the original request's information will be found in the following request attributes:
javax.servlet.forward.request_uri
javax.servlet.forward.context_path
javax.servlet.forward.servlet_path
javax.servlet.forward.path_info
javax.servlet.forward.query_string
These are set out in section 8.3 and 8.4 of the Servlet 2.4 specification.
However, be aware that this information is only preserved for internally-dispatched requests. If you have a front-end web-server, or dispatch outside of the current container, these values will be null. In other words, you may have no way to find the original request URL.