java - how to display image which is outside server directory in strtus

Question

This question is continuation to my previous question Accessing External Files Into Our Web Application, actually I am uploading file using struts tag <html:file property="file" />

But now I wanted to show the uploaded images from that location but I am getting src location as http://localhost:9443/D:/resources/images/img1.jpg which is not a valid path for that image.

How to access that image which is outside my server directory.

This is how I am sending Ajax response with Absolute path of images

public ActionForward getAjaxUploadedFiles(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception
    {

        String imagePath = "D:/resources/images/";
        ArrayList<String> path = new ArrayList<String>();

        File imageFile = new File(imagePath);
        File imageFiles[] = imageFile.listFiles();

        for (int i = 0; i < imageFiles.length; i++) {
            path.add(imageFiles[i].getAbsolutePath());
        }

        PrintWriter out = response.getWriter();
        response.setContentType("text/xml");
        response.setHeader("Cache-Control", "no-cache");
        response.setStatus(HttpServletResponse.SC_OK);

        StringBuffer strXMl = new StringBuffer();
        strXMl.append("<?xml version="1.0" encoding="UTF-8"?>");
        strXMl.append("<start>"); 


        for (String imagePth : path) {
            strXMl.append("<imagePath>");
            strXMl.append(imagePth);
            strXMl.append("</imagePath>");
        }

        strXMl.append("</start>");

        if(strXMl != null){ 
            String Xml = strXMl.toString();
            out.write(Xml);
            System.err.println("XMl Reponse is: " + Xml);
        }
        else {
            response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
        }
        out.flush();

        return mapping.findForward(null);
    }

This is how I am rendering images at JSP

 $(response).find("imagePath").each(function() {
            row = tblReportList.insertRow(0);
            row.className="TableBordergray";
            row.style.width="100%";

            var imagePath = $(this).text();

            cell = row.insertCell(0);
            cell.innerHTML="<img src='" + imagePath + "' alt='" + imagePath + "' height='42' width='42'>";
        });

but at img tag I am getting image path as http://localhost:9443/D:/resources/images/img1.jpg

Answer 1

Hi Below is the answer to my question, I have created ImageServlet for displaying image, steps to perform:

1. you need to add mapping in web.xml file:

    <servlet-name>ImageServlet</servlet-name>
    <url-pattern>/ImageServlet/*</url-pattern>

2. create ImageServlet:

public class ImageServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {

        //Setting image path
        ImageLocationService locationService = new ImageLocationService();

        try {
            String imageCategory = request.getParameter("imageCategory");
            if (imageCategory != null) {
                this.imagePath = locationService.getImageLocation(imageCategory);
            }else{
                this.imagePath = ConfigConstants.imageLocation;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        // Get requested image by path info.
        String requestedImage = request.getPathInfo();

        // Check if file name is actually supplied to the request URI.
        if (requestedImage == null) {
            // Do your thing if the image is not supplied to the request URI.
            // Throw an exception, or send 404, or show default/warning image, or just ignore it.
            response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
            return;
        }

        // Decode the file name (might contain spaces and on) and prepare file object.
        File image = new File(imagePath, URLDecoder.decode(requestedImage, "UTF-8"));

        // Check if file actually exists in filesystem.
        if (!image.exists()) {
            // Do your thing if the file appears to be non-existing.
            // Throw an exception, or send 404, or show default/warning image, or just ignore it.
            response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
            return;
        }

        // Get content type by filename.
        String contentType = getServletContext().getMimeType(image.getName());

        // Check if file is actually an image (avoid download of other files by hackers!).
        // For all content types, see: http://www.w3schools.com/media/media_mimeref.asp
        if (contentType == null || !contentType.startsWith("image")) {
            // Do your thing if the file appears not being a real image.
            // Throw an exception, or send 404, or show default/warning image, or just ignore it.
            response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
            return;
        }

        // Init servlet response.
        response.reset();
        response.setBufferSize(DEFAULT_BUFFER_SIZE);
        response.setContentType(contentType);
        response.setHeader("Content-Length", String.valueOf(image.length()));
        response.setHeader("Content-Disposition", "inline; filename="" + image.getName() + """);

        // Prepare streams.
        BufferedInputStream input = null;
        BufferedOutputStream output = null;

        try {
            // Open streams.
            input = new BufferedInputStream(new FileInputStream(image), DEFAULT_BUFFER_SIZE);
            output = new BufferedOutputStream(response.getOutputStream(), DEFAULT_BUFFER_SIZE);

            // Write file contents to response.
            byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
            int length;
            while ((length = input.read(buffer)) > 0) {
                output.write(buffer, 0, length);
            }
        } finally {
            // Gently close streams.
            close(output);
            close(input);
        }
    }

    private static void close(Closeable resource) {
        if (resource != null) {
            try {
                resource.close();
            } catch (IOException e) {
                // Do your thing with the exception. Print it, log it or mail it.
                e.printStackTrace();
            }
        }
    }
}

3. At jsp side you need to add the mapping in step 1 in your img tag i.e. input type='image':

<input  type="image" alt='No image found' src='../ImageServlet/append image name that you want to display' />

You can even create Action class and use execute method for doing the same.