Setting the file name of a resource to be downloaded

Question

Hi,
I am trying to download files from the webserver to the client machine using code given below..
The filename is the path to the file to be downloaded to the client. Some parsing of the filename is required as I modify the filename to a particular format. I use the parsed filename to get the Mime type which is then set to the content type.
When I tested the code, the mime type is correct and also the file downloaded is corrext. But the browser prompts me to save the file with the name of the Url. Can I change this? I suppose setting of some http response header is needed.
public class ReadServlet extends GenericServlet {
    public void service(ServletRequest req, ServletResponse res){
               ServletContext context = this.getServletContext();
               //check doc_id and doc_ver_index
               String filename = (String)req.getAttribute("filename");
               if(filename == null ){
                    return;
               try{
                    File file = new File(filename);
                    int underscore = filename.lastIndexOf('_');
                    if(underscore!=-1){
                         filename = filename.substring(0, underscore);
                    String mimeType = context.getMimeType(filename);
                    if(mimeType == null){
                         mimeType = "application/octet-stream";
                    res.setContentType(mimeType);
                    InputStream in = null;
                    OutputStream out = res.getOutputStream();
                    byte[] buffer = new byte[1024*8];
                    try {
                         in = new BufferedInputStream(new FileInputStream(file) );
                         int ch;
                         while ((ch = in.read(buffer)) !=-1) {
                              out.write(buffer, 0, ch );
                    finally {
                         if (in != null){
                              in.close();
                         if(out!=null){
                              out.close();
               }catch(IOException ioe){
                    System.out.println(ioe.getMessage());
          return;
}Thanks
Rahul

Answer 1

Hi Rahul,
res.setHeader("Content-Disposition", "attachment; filename=\"" + your_file_name + "\"");
res.setContentLength(your_file_length);Good luck.