Get file extension from uploaded file

Question

Here my requirement is to upload the file and to store it in the disk. I have no problem in storing it in disk, but getting the extension of the file. The problem is when I clic

Answer 1

I used Jquery fileupload in client side.

And at my JS file ,

function doUploadPhoto(seq) {
$('#fileupload').fileupload({
    url : 'news/upload.html?s=' + seq,
    sequentialUploads : true,
    disableImageResize : false,
    imageMaxWidth : 1024,
    imageMaxHeight : 1024,
    previewCrop : true,
    dropZone : $("#dropZone"),
    acceptFileTypes : /(\.|\/)(gif|jpe?g|png)$/i,
    progress : function(e, data) {
        if (data.context) {
            var progress = data.loaded / data.total * 100;
            progress = Math.floor(progress);
            $('.progress').attr('aria-valuenow', progress);
            $('.progress').css('display', 'block');
            $('.bar').css('width', progress + '%');
        }
    },
    progressall : function(e, data) {
        var progress = data.loaded / data.total * 100;
        progress = Math.floor(progress);
        $('.progressall').attr('aria-valuenow', progress);
        $('.progressall').css('display', 'block');
        $('.allbar').css('width', progress + '%');
        if (progress > 20) {
            $('.allbar').text(progress + '% Completed');
        }
    },
    stop: function (e) {
        return;
    }
});
}

Handle your specific request for image upload (I used Spring).

@RequestMapping(value = "/news/upload.html", method = RequestMethod.POST)
public final void uploadNewsPhoto(final HttpServletRequest request, final HttpServletResponse response)
        throws Exception {
    doUploadNewsPhoto(request, getSessionFileItems(request));
}

for upload image

public final synchronized String doUploadNewsPhoto(final HttpServletRequest request,
        final List sessionFiles) throws UploadActionException {

    try {
        List> ret = new ArrayList>();
        for (FileItem item : sessionFiles) {
            if (!item.isFormField()) {
                try {
                    // get news sequence for save it's images
                    Long seq = Long.parseLong(request.getParameter("s"));
                    Map res = newsPhotoBiz.saveToFile(seq, item, SecuritySession.getLoginUserSeq());

                    res.put("name", item.getName());
                    res.put("size", item.getSize());
                    ret.add(res);
                }
                catch (Exception e) {
                    log.error("Error, can't upload news photo file, name:" + item.getName(), e);
                }
            }
        }

        // Remove files from session because we have a copy of them
        removeSessionFileItems(request);

        Map json = new HashMap();
        json.put("files", ret);
        JSONObject obj = (JSONObject) JSONSerializer.toJSON(json);
        // return to client side about uploaded images info
        return obj.toString();
    }
    catch (Exception e) {
        log.error("Error, when upload news photo file", e);
        throw new UploadActionException(e);
    }
}

for save image

public final Map saveToFile(final Long newsSeq, final FileItem item, final Long loginUserSeq)
        throws BusinessException {
    String staticDir = System.getProperty("staticDir");

    Date today = new Date();
    SimpleDateFormat fmtYMD = new SimpleDateFormat("/yyyyMMdd");
    SimpleDateFormat fmtHMS = new SimpleDateFormat("HHmmssS");

    String saveDir = "data/news" + fmtYMD.format(today);
    String format = ".jpg";
    try {
        format = item.getName().substring(item.getName().lastIndexOf("."), item.getName().length());
    }
    catch (Exception e) {
      format = ".jpg";
    }

    try {
        String fileName = newsSeq + "_" + fmtHMS.format(today) + format;

        NewsPhotoBean bean = new NewsPhotoBean();
        bean.setNewsSeq(newsSeq);
        bean.setFile(saveDir + "/" + fileName);
           // save image infos in database and return it's sequence
        Long photoSeq = newsPhotoService.add(bean, loginUserSeq);

        // Save image in specify location
        String filePath = staticDir + "/" + saveDir;
        FileSupport.saveFile(filePath, fileName, item);

        Map ret = new HashMap();
        ret.put("seq", newsSeq);
        ret.put("photoSeq", photoSeq);
        ret.put("path", saveDir + "/" + fileName);
        ret.put("ext", format.substring(1));

       //client side may need uploaded images info
        return ret;
    }
    catch (Exception e) {
        throw new BusinessException("Error occur when save file. newsSeq : " + newsSeq, e);
    }
}

for write image

// Save Image by FileItem that gets from Image Upload
public static String saveFile(final String filePath, final String fileName, final FileItem item) throws Exception {
    File file = new File(filePath);
    file.setExecutable(true, false);
    file.setWritable(true, false);

    if (!file.exists()) {
        file.mkdirs();
    }

    File imageFile = new File(file, fileName);
    item.write(imageFile);
    item.setFieldName(filePath + fileName);

    return item.toString();
}