Downloading files using Download Manager in Android
Download Manager
Download Manager is a system service which allows to handle long-running HTTP downloads in the background and notify the triggering application via a broadcast receiver once the download is finished. It was introduced in Android 2.3. (API 9).
Download manager helps use reduce the burden of writing our own download service with all those error handling. In this tutorial we will see how to create a download manager to download a file in background and notify the application once the file is downloaded.
Source code is provided at the end of this article. You may download and check out yourself.
First, Add the Download Manager in your onCreate().
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downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); |
Single File Download
For downloading a single file, follow the below mentioned code.
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btnSingle.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Download_Uri = Uri.parse("http://www.gadgetsaint.com/wp-content/uploads/2016/11/cropped-web_hi_res_512.png"); DownloadManager.Request request = new DownloadManager.Request(Download_Uri); request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE); request.setAllowedOverRoaming(false); request.setTitle("GadgetSaint Downloading " + "Sample" + ".png"); request.setDescription("Downloading " + "Sample" + ".png"); request.setVisibleInDownloadsUi(true); request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "/GadgetSaint/" + "/" + "Sample" + ".png"); refid = downloadManager.enqueue(request); } }); |
In the above code, We are passing a request to the Download Manager with the download file URL, Title and Description to be shown in notification bar etc. We can also specify whether the download should happen over wifi or cellular or both.
Multiple file Downloads
Downloading multiple files is easy. just need to add the above request in a loop. The download requests will be added into the queue.
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for(int i = 0; i < 2; i++) { Download_Uri = Uri.parse("http://www.gadgetsaint.com/wp-content/uploads/2016/11/cropped-web_hi_res_512.png"); DownloadManager.Request request = new DownloadManager.Request(Download_Uri); request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE); request.setAllowedOverRoaming(false); request.setTitle("GadgetSaint Downloading " + "Sample_" + i + ".png"); request.setDescription("Downloading " + "Sample_" + i + ".png"); request.setVisibleInDownloadsUi(true); request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "/GadgetSaint/" + "/" + "Sample_" + i + ".png"); refid = downloadManager.enqueue(request); } |
In the above code sample, I am using a single download url in the loop. You may use multiple urls depending on your requirements by adding it in a list and iterating it.
Listening to Download Complete
You may listen when a download is completed and perform some actions like showing a download completed notification. In order to do that you need to keep a track of the refid that we get while enqueuing the download requests. After every enqueue add the refid into an Array list as shown below.
Create an Arraylist of type long.
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ArrayList<Long> list = new ArrayList<>(); |
And add the refid whenever you request the download manager
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refid = downloadManager.enqueue(request); // add the refid into an arraylist list.add(refid); |
Now create a Broadcast Receiver to listen to the “Download Completed” Broadcasts. This will be triggered everytime a download is completed.
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BroadcastReceiver onComplete = new BroadcastReceiver() { public void onReceive(Context ctxt, Intent intent) { // get the refid from the download manager long referenceId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1); // remove it from our list list.remove(referenceId); // if list is empty means all downloads completed if (list.isEmpty()) { // show a notification Log.e("INSIDE", "" + referenceId); NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(MainActivity.this) .setSmallIcon(R.mipmap.ic_launcher) .setContentTitle("GadgetSaint") .setContentText("All Download completed"); NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); notificationManager.notify(455, mBuilder.build()); } } }; |
In OnCreate, Register the receiver like below
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registerReceiver(onComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE)); |
In onDestroy, unRegister the receiver,
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@Override protected void onDestroy() { super.onDestroy(); unregisterReceiver(onComplete); } |
Permissions
Don’t forget to add the following permissions in the Manifest file. If you are using Android 6 or above, Handle the Permissions.
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<uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> |
For more clarifications, Checkout the source code from Github below.
Preview
SourceCode
Download the source code from Github
Let me know your Suggestions / Queries in comments.
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Hello,
Thanks for this post. But I want to download files in my own Client. Don’t use Mobile’s download Client or manager. Is it possible? Please help me.
Yes its possible. https://stackoverflow.com/questions/1714761/download-a-file-programmatically-on-android
thank you for this wonderful tutorial.Please help me i want to show multiple progress bars with percentage in listview for Multiple file Downloads.If i close the app when i return i need updated progress bars with percentage.I know that this service goes on even app is closed.
Thanking you for this wonderful tutorial.Please help me i want to show multiple progress bars with percentage in listview for Multiple file Downloads.If i close the app when i return i need updated progress bars with percentage.I know that this service goes on even app is closed.