How to download BLOB from MySQL using Spring MVC framework

Question

I have created the code for uploading a pdf file into the BLOB of MySQL database.

HTML Code:

<form method="post" action="doUpload" enctype="multipart/form-data">
    <table border="0">
        <tr>
            <td>Pick file #1:</td>
            <td><input type="file" name="fileUpload" size="50" /></td>
        </tr>
        <tr>
             <td colspan="2" align="center"><input type="submit" value="Upload" /></td>
        </tr>
     </table>
</form>

Spring Controller:

@RequestMapping(value = "/doUpload", method = RequestMethod.POST)
public String handleFileUpload(HttpServletRequest request,
        @RequestParam CommonsMultipartFile[] fileUpload) throws Exception {

    if (fileUpload != null && fileUpload.length > 0) {
        for (CommonsMultipartFile aFile : fileUpload) {
            System.out.println("Saving file: " + aFile.getOriginalFilename());
            UploadFile uploadFile = new UploadFile();
            uploadFile.setFileName(aFile.getOriginalFilename());
            uploadFile.setData(aFile.getBytes());
            fileUploadDao.save(uploadFile);                
        }
    }
    return "Success";
}

I could able to upload the PDF File into the blob field of MySQL table. But I don't know how to retrieve the blob data, as a hyperlink, where I can click the link and download the pdf file. Kindly help me.

draysams · Accepted Answer · 2018-10-26 11:25:28Z

You can try fetching the document content from MySQL and then set the data stream in the response object.

Using a response.setHeader() method to set "Content-Disposition" will launch the Save As dialog in the browser for the user to download the file.

@RequestMapping("/retrieve/{fileName}")
public String download(@PathVariable("fileName")
        String fileName, HttpServletResponse response) {

    DownloadFile downloadDocument = downloadFileDao.get(fileName);
    try {
        response.setHeader("Content-Disposition", "inline; filename=\"" + fileName + "\"");
        OutputStream out = response.getOutputStream();
        response.setContentType(downloadDocument.getContentType());
        IOUtils.copy(downloadDocument.getContent().getBinaryStream(), out);
        out.flush();
        out.close();

    } catch (SQLException e) {
        System.out.println(e.toString());
        //Handle exception here
    } catch (IOException e) {
        System.out.println(e.toString());
        //Handle exception here
    }

    return "Success";
}

Collectives™ on Stack Overflow

How to download BLOB from MySQL using Spring MVC framework

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related