Create and Download Excel from Web Explorer with Java in Spring MVC

Question

I want to create an Excel file from a method in Java and download it in a browser.

I have found an example on this post where you create the Excel file, but I want to create the .xls file and download it from a web browser.

How can I do that?

Do you mean you would like to download the file in a web browser? Or you would like to visualize the excel file in a web browser? — pmartin8, Sep 23 '15 at 16:00
Just download the created file in a location in my PC, just like a regular download... — CyborgNinja23, Sep 23 '15 at 16:02
Where will the file be? Locally on your machine, or somewhere on a server? — pmartin8, Sep 23 '15 at 16:09
Just type this in your browser : file:///C:/path_to_your_file.xls then you will download the file... It has nothing to do with Java or Excel though. — pmartin8, Sep 23 '15 at 16:12
I'm sorry, I am not being very clear, I want to create the file from a method in java first... — CyborgNinja23, Sep 23 '15 at 16:16
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/90454/discussion-between-pmartin8-and-geme23). — pmartin8, Sep 23 '15 at 16:40

score 5 · Accepted Answer · answered Sep 23 '15 at 19:16

I finally found a solution for my problem...!!

This is working for me:

       @RequestMapping("/downloadFile")
       public void downloadFile(HttpServletRequest request, HttpServletResponse response) {             

       try {

            String fileName = "C:/excelFile.xls";
            HSSFWorkbook workbook = new HSSFWorkbook();
            HSSFSheet sheet = workbook.createSheet("firstSheet");

            HSSFRow rowhead = sheet.createRow((short) 0);
            rowhead.createCell(0).setCellValue("No.");
            rowhead.createCell(1).setCellValue("Name");
            rowhead.createCell(2).setCellValue("Address");
            rowhead.createCell(3).setCellValue("Email");

            HSSFRow row = sheet.createRow((short) 1);
            row.createCell(0).setCellValue("1");
            row.createCell(1).setCellValue("Carlos");
            row.createCell(2).setCellValue("Costa Rica");
            row.createCell(3).setCellValue("myNameh@gmail.com");

            FileOutputStream fileOut = new FileOutputStream(fileName);
            workbook.write(fileOut);
            fileOut.close();
            System.out.println("Your excel file has been generated!");

            //Code to download
            File fileToDownload = new File(fileName);
            InputStream in = new FileInputStream(fileToDownload);

            // Gets MIME type of the file
            String mimeType = new MimetypesFileTypeMap().getContentType(fileName);

            if (mimeType == null) {
                // Set to binary type if MIME mapping not found
                mimeType = "application/octet-stream";
            }
            System.out.println("MIME type: " + mimeType);

            // Modifies response
            response.setContentType(mimeType);
            response.setContentLength((int) fileToDownload.length());

            // Forces download
            String headerKey = "Content-Disposition";
            String headerValue = String.format("attachment; filename=\"%s\"", fileToDownload.getName());
            response.setHeader(headerKey, headerValue);

            // obtains response's output stream
            OutputStream outStream = response.getOutputStream();

            byte[] buffer = new byte[4096];
            int bytesRead = -1;

            while ((bytesRead = in.read(buffer)) != -1) {
                outStream.write(buffer, 0, bytesRead);
            }

            in.close();
            outStream.close();

            System.out.println("File downloaded at client successfully");


        } catch (Exception ex) {
            System.out.println(ex);
        }
    }

score 0 · Answer 2 · answered Sep 23 '15 at 16:29

0

If you want to trigger a Java process from a Web Browser (HTTP request), then you need an application server (like Tomcat) to accept your HTTP request and execute some server-side code (Servlet). A main method like in the example cannot be launched by a HTTP request. Look here if you never wrote a Servlet before.

answered Sep 23 '15 at 16:29

pmartin8

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2

Now, you see how important it is to be clear in the original question. – pmartin8 Sep 23 '15 at 16:36

score -1 · Answer 3 · edited May 23 '17 at 11:46

This has nothing to do with Excel, but this post shows how to download a file from a Spring MVC controler.

    @RequestMapping(value = "/files/{file_name}", method = RequestMethod.GET)
    public void getFile(@PathVariable("file_name") String fileName, HttpServletResponse response) {
    try {
      // get your file as InputStream
      InputStream is = ...;
      // copy it to response's OutputStream
      org.apache.commons.io.IOUtils.copy(is, response.getOutputStream());
      response.flushBuffer();
    } catch (IOException ex) {
      log.info("Error writing file to output stream. Filename was '{}'", fileName, ex);
      throw new RuntimeException("IOError writing file to output stream");
    }
}

Create and Download Excel from Web Explorer with Java in Spring MVC

3 Answers3