Download file from base64 url in android webview
I could manage to save base64 encoded data as a file. So, the basic short answer to my question was decoding encoded data to bytes and writing it to a file like this:
String base64EncodedString = encodedDataUrl.substring(encodedDataUrl.indexOf(",") + 1); byte[] decodedBytes = Base64.decode(base64EncodedString, Base64.DEFAULT); OutputStream os = new FileOutputStream(file); os.write(decodedBytes); os.close();
Just for reference for others who may come up with the same question I am adding my final code below. Inside onCreate()
method i am handling file downloads like this:
webView.setDownloadListener(new DownloadListener() {
@Override
public void onDownloadStart(String url, String userAgent,
String contentDisposition, String mimeType,
long contentLength) {
if (url.startsWith("data:")) { //when url is base64 encoded data
String path = createAndSaveFileFromBase64Url(url);
return;
}
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
request.setMimeType(mimeType);
String cookies = CookieManager.getInstance().getCookie(url);
request.addRequestHeader("cookie", cookies);
request.addRequestHeader("User-Agent", userAgent);
request.setDescription(getResources().getString(R.string.msg_downloading));
String filename = URLUtil.guessFileName(url, contentDisposition, mimeType);
request.setTitle(filename);
request.allowScanningByMediaScanner();
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, filename);
DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
dm.enqueue(request);
Toast.makeText(getApplicationContext(), R.string.msg_downloading, Toast.LENGTH_LONG).show();
}
});
And createAndSaveFileFromBase64Url()
method which deals with base64 encoded data looks like this:
public String createAndSaveFileFromBase64Url(String url) {
File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);
String filetype = url.substring(url.indexOf("/") + 1, url.indexOf(";"));
String filename = System.currentTimeMillis() + "." + filetype;
File file = new File(path, filename);
try {
if(!path.exists())
path.mkdirs();
if(!file.exists())
file.createNewFile();
String base64EncodedString = url.substring(url.indexOf(",") + 1);
byte[] decodedBytes = Base64.decode(base64EncodedString, Base64.DEFAULT);
OutputStream os = new FileOutputStream(file);
os.write(decodedBytes);
os.close();
//Tell the media scanner about the new file so that it is immediately available to the user.
MediaScannerConnection.scanFile(this,
new String[]{file.toString()}, null,
new MediaScannerConnection.OnScanCompletedListener() {
public void onScanCompleted(String path, Uri uri) {
Log.i("ExternalStorage", "Scanned " + path + ":");
Log.i("ExternalStorage", "-> uri=" + uri);
}
});
//Set notification after download complete and add "click to view" action to that
String mimetype = url.substring(url.indexOf(":") + 1, url.indexOf("/"));
Intent intent = new Intent();
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(file), (mimetype + "/*"));
PendingIntent pIntent = PendingIntent.getActivity(this, 0, intent, 0);
Notification notification = new NotificationCompat.Builder(this)
.setSmallIcon(R.mipmap.ic_launcher)
.setContentText(getString(R.string.msg_file_downloaded))
.setContentTitle(filename)
.setContentIntent(pIntent)
.build();
notification.flags |= Notification.FLAG_AUTO_CANCEL;
int notificationId = 85851;
NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(notificationId, notification);
} catch (IOException e) {
Log.w("ExternalStorage", "Error writing " + file, e);
Toast.makeText(getApplicationContext(), R.string.error_downloading, Toast.LENGTH_LONG).show();
}
return file.toString();
}