Android: How to use download manager class?

Question

I want to download a binary file from a url. Is it possible to use the Android download manager class that I found here DownloadManager class?

Answer 1

Is it possible to use the android download manager class that i found here

Yes, though that is only available since Android API Level 9 (version 2.3). Here is a sample project demonstrating the use of DownloadManager.

Answer 2

Use DownloadManager class (GingerBread and newer only)

GingerBread brought a new feature, DownloadManager, which allows you to download files easily and delegate the hard work of handling threads, streams, etc. to the system.

First, let's see a utility method:

/**
 * @param context used to check the device version and DownloadManager information
 * @return true if the download manager is available
 */
public static boolean isDownloadManagerAvailable(Context context) {

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
        return true;
    }
    return false;
}

Method's name explains it all. Once you are sure DownloadManager is available, you can do something like this:

String url = "url you want to download";
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
request.setDescription("Some descrition");
request.setTitle("Some title");
// in order for this if to run, you must use the android 3.2 to compile your app
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
    request.allowScanningByMediaScanner();
    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
}
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "name-of-the-file.ext");

// get download service and enqueue file
DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
manager.enqueue(request);

Download progress will be showing in the notification bar.

Answer 3

Make sure the READ_EXTERNAL_STORAGE and WRITE_EXTERNAL_STORAGE permissions is in your Manifest.xml file:

And then include this code in your download function

if(ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED || ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){

  // this will request for permission when user has not granted permission for the app 
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1); 
}

else{ 
     //Download Script

DownloadManager downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);       
Uri uri = Uri.parse("URL of file to download");         
DownloadManager.Request request = new DownloadManager.Request(uri);        
 request.setVisibleInDownloadsUi(true);        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);        
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, uri.getLastPathSegment());        
downloadManager.enqueue(request);
 }

Answer 4

DownloadManager downloadmanager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
Uri uri = Uri.parse("http://www.example.com/myfile.mp3");
DownloadManager.Request request = new DownloadManager.Request(uri);
request.setTitle("My File");
request.setDescription("Downloading");
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationUri(Uri.parse("file://" + folderName + "/myfile.mp3"));
downloadmanager.enqueue(request);