Android DownloadManager "Impossible to open file"

Question

I'm using DownloadManager to download a file from a webService. The download end successfuly, but when I try to open the new file in the "download" folder I've got this error "Impossible to open file" (and I know I can open this type of file).

Also, when I plug my phone to my computer and when I open the download file with it, the file open successfuly and is not corrupted.

I don't have other error, so I'm really lost !

Here my code:

    /*Data*/
    int filePosition = position - _subFolderNameList.length;
    String url = _folder.getFiles().get(filePosition).getUrl();
    String FileName = _folder.getFiles().get(filePosition).getName();
    String Description = _folder.getFiles().get(filePosition).getUrl();

    /*Prepare request*/
    DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
    request.setDescription(Description);
    request.setTitle(FileName);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
        request.allowScanningByMediaScanner();
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
    }
    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, FileName);

    DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
    manager.enqueue(request); // Send request

Edit: Permission in the Manifest:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />

Sternson

what type of file are you downloading? and how are you trying to "open" it? You've only posted code for downloading. – Combo

I try to downloading all kind of extension but for the test I only try with file like PDF because I know I can open it with my phone. To open it I just go in the download folder (with my phone) and I just click on the file. – Sternson

Have you ensured you can open .pdf files, downloaded by hand with your phone (Maybe theres just no app installed to handle the VIEW Intent)? Because I couldnt open many file types with my device by default... – Cytologist

Yes I am, because I trie to download the same files with others application (e.g google chrome), and when I open it in the download folder that works. Also I can't open images (JPEG, PNG etc.) download by my app too. I guess it's a reading permission problem or that the file isn't recognized by his extension but it's weird. – Sternson

Answer 1

Okay I found the problem !

I had to specify the "MIME content type" of the file using setMimeType().

public DownloadManager.Request setMimeType (String mimeType);

Sternson

Hi, not sure if you still around SOF, but if you are downloading from a link to file which you don't know what file extension is that, how do you know which MIME type to set? – Overstock

Answer 2

Yes you have to specify the MIME type. Adding a few more details to the accepted answer.

public DownloadManager.Request setMimeType (String mimeType);

To get MIME type you can use the following function.

private String getMimeFromFileName(String fileName) {
    MimeTypeMap map = MimeTypeMap.getSingleton();
    String ext = MimeTypeMap.getFileExtensionFromUrl(fileName);
    return map.getMimeTypeFromExtension(ext);
}

and the following is the Xamarin.Android implementation of the same :

        private static string GetMimeTypeFromFileName(string fileName)
        {
            var map = MimeTypeMap.Singleton;
            var ext = MimeTypeMap.GetFileExtensionFromUrl(fileName);
            return map.GetMimeTypeFromExtension(ext);
        }

Clouded