Bug in context based forward?

Question

I have a servlet that is forwarding to a .jsp page. I do this using
          the getServletContext().getRequestDispatcher( "/my.jsp" ). Note that
          this is in a web application, not a servlet defined in
          weblogic.properties and the files for this web application are stored
          on a completely different directory location than the default server
          doc root directory. In order to avoid having problems with relative
          URL's in the destination JSP page, I changed one of the images which
          has a link in it to use a path relative to the root of the server -
          i.e. something like /index.jsp.
          The first thing that I noticed was that the URL (unlike what the spec
          says) for the destination page in the browser changed to the url for
          the forwarded to page (vs staying with the request URL as the spec
          says) - but that is really beside the point of this post ... the real
          problem is that when I click on that image to take me to that page,
          the URL that is formed lacks the web application context component -
          thus Weblogic tries to find it in the public_html subdirectory and of
          course returns a 404 error since the document is stored off of the web
          application's directory, not the root directory of the web server.
          I am running SP5 WLS 5.1.
          Is this a bug - or am I misinterpreting the spec?
          

Answer 1

Hi Scott,
          It is typical to access your servlets via the following form:
          http://www.myco.com/myapp/stuff
          ... where "stuff" must not contain "/" characters. Usually "stuff" will be
          mapped (via web.xml) to a servlet. I usually use a front servlet, so my
          web.xml maps "*" to that front servlet, and the front servlet then is
          responsible for its own mapping from that point. I usually put security on
          *.jsp to an admin group, so that they are not accessible directly. That way
          all requests go through my front servlet.
          HTML returned by the servlet (regardless of how gen'd, for example by fw to
          a jsp) should contain relative paths to the images only if the images are
          under:
          http://www.myco.com/myapp/
          For example, in a small WAR (i.e. conventional, not nuclear) you might put
          your .jsp files in the root of the WAR and your images in a sub-directory
          called /img. In such a case, your servlet is doing a forward:
          forward("/my.jsp")
          ... and the JSP formats HTML containing images such as:
          src="img/my.gif"
          I personally prefer:
          src="<App:ImagePath/>my.gif"
          ... but that takes a bit more work to implement and manage.
          Cameron Purdy
          [email protected]
          http://www.tangosol.com
          WebLogic Consulting Available
          "Scott Jacobs" <[email protected]> wrote in message
          news:[email protected]...
          > Correction - the URL displayed in the browser is not incorrect as I
          > stated below - it is ok. However, any root relative path I attempt to
          > use causes the server to look at the actual web server root, and not
          > the root of the web application.
          >
          > Note also that I have tried using the request.getRequestDispatcher()
          > method as well, using relative paths for the url passed to that
          > dispatcher along with relative URL's for links, etc. in the .jsp
          > pages. That approach works, except that if I go from index.jsp
          > (accessed directly), then to register.jsp (forwarded to by servlet),
          > and then back to index.jsp via image link on register.jsp page, I now
          > have the path of the servlet in the url for the index page. If I then
          > go to the register page again, I get another path component
          > corresponding to the servlet added to the url displayed, and so on.
          >
          > How the heck do I prevent this - do I have to go in and modify the
          > links on the forwarded to JSP page so that they "get rid" of the
          > servlet component of the path by using "../". This would be a pain
          > since most of these links are in common header and nav bar areas. That
          > would mean that I would have to have at least two sets of those
          > depending on whether the page was forwarded to by my control servlet
          > or not...yuck!
          >
          > On Thu, 14 Sep 2000 02:33:32 GMT, [email protected] (Scott Jacobs)
          > wrote:
          >
          > >I have a servlet that is forwarding to a .jsp page. I do this using
          > >the getServletContext().getRequestDispatcher( "/my.jsp" ). Note that
          > >this is in a web application, not a servlet defined in
          > >weblogic.properties and the files for this web application are stored
          > >on a completely different directory location than the default server
          > >doc root directory. In order to avoid having problems with relative
          > >URL's in the destination JSP page, I changed one of the images which
          > >has a link in it to use a path relative to the root of the server -
          > >i.e. something like /index.jsp.
          > >
          > >The first thing that I noticed was that the URL (unlike what the spec
          > >says) for the destination page in the browser changed to the url for
          > >the forwarded to page (vs staying with the request URL as the spec
          > >says) - but that is really beside the point of this post ... the real
          > >problem is that when I click on that image to take me to that page,
          > >the URL that is formed lacks the web application context component -
          > >thus Weblogic tries to find it in the public_html subdirectory and of
          > >course returns a 404 error since the document is stored off of the web
          > >application's directory, not the root directory of the web server.
          > >
          > >I am running SP5 WLS 5.1.
          > >
          > >Is this a bug - or am I misinterpreting the spec?
          >