Question

I’ve got a resource aware spring mvc portlet that I’m using to serve a PDF. Previously our method for serving PDFs from a portlet has been to link to a servlet to actually write the PDF response. Our pattern in the servlets was basically this:

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        OutputStream out = response.getOutputStream();
        FileInputStream certIn = null;
        try {
            certIn = new FileInputStream(pdfFile);
            if (certIn.available() > 0) {
                while (certIn.available() > 0) {
                    out.write(certIn.read());
                }
                out.flush();
            }                       
        } catch (IOException e) {
            response.reset();
            response.setContentType("text/html");
            getServletContext().getRequestDispatcher("/WEB-INF/jsp/error.jsp").include(request, response);
        } finally {
            if (certIn != null) {
                try {
                    certIn.close();
                } catch (IOException e) {
                    LOG.warn(
                            "Failed to close FileInputStream", e);
                }
            }
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    LOG.warn("Failed to close ServletOutputStream", e);
                }
            }
        }
    }

I’m now trying to replicate this in the resource aware portlet. The problem I’ve got is if we get an error, I can’t get it to redirect to the error jsp.

If I use the portletContext.getRequestDispatcher() to forward to a jsp, I get an error saying I can’t call getWriter() after getOuputStream(). I get the same error if I try to return a spring ModelAndView to the error.jsp.

Can anyone suggest how I can redirect the user to a jsp after calling getOutputStream() on the ResourceResponse?

Thanks.

Answer 1

Changed the order of what I was doing slightly in the end. Now don’t call getPortletOutputStream() until I know the file exists and is readable. If it fails whilst actually writing to the output stream it cannot serve the jsp, but that’s the case for the servlet too.