DownloadManager.ACTION_DOWNLOAD_COMPLETE broadcast receiver receiving same download id more than once with different download statuses in Android

问题

I am using Android DownloadManger System Service for downloading some files in following way

dwnId = mgr.enqueue(new DownloadManager.Request(serveruri)
        .setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI |
                DownloadManager.Request.NETWORK_MOBILE)
                .setAllowedOverRoaming(false)
                .setTitle(getAlbumName())
                .setDescription(getTrackName())
                .setDestinationUri(deviceUri)
                .setShowRunningNotification(true));

where mgr is Download Manager instance, dwnId is unique ID returned. I am also registering for ACTION_DOWNLOAD_COMPLETE

registerReceiver(onDownloadComplete, new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));

and in the onDownloadComplete BroadcastReceiver's onReceive() method I am getting download Id like

Long dwnId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, 0);

After that I am querying Download Manager for Download status

Cursor c = downloadManager.query(new DownloadManager.Query().setFilterById(dwnId)); c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));

for DownloadManager.STATUS_* constants.

The problem is I am receiving the same downId twice (means onReceive method is called twice), once with DownloadManager.STATUS_SUCCESSFUL status and once with DownloadManager.STATUS_FAILED status for same dwnId. I am issuing request to download some 10 files at a time and but on device download manager it is showing the download count as some 12 or 13 in the notification bar top left means. I think that Download manager has some problem in downloading files and resumed or automatically restarted to download the same file again. Thats why there is a difference between the files count I requested to download and actual number in download queue. Because of this only I am getting same DownloadId complete action twice. If this is true, how to restrict it. Am I wrong what might be the reason for count difference between what I requested to actual download? Why is the broadcast receiver receiving the same download Id twice. Can anybody please let me know?

Thanks In Advance...

回答1:

This is a reported bug see: http://code.google.com/p/android/issues/detail?id=18462

The way around I found is to verify if the download was a success, if not ditch the intent or re-queue the file if it was never downloaded...

Lost a couple of hours figuring that one :(

** Edit: adding code example **

/**
 * Check if download was valid, see issue
 * http://code.google.com/p/android/issues/detail?id=18462
 * @param long1
 * @return
 */
private boolean validDownload(long downloadId) {

    Log.d(TAG,"Checking download status for id: " + downloadId);

    //Verify if download is a success
    Cursor c= dMgr.query(new DownloadManager.Query().setFilterById(downloadId));

    if(c.moveToFirst()){            
        int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));

        if(status == DownloadManager.STATUS_SUCCESSFUL){
            return true; //Download is valid, celebrate
        }else{
            int reason = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_REASON));
            Log.d(TAG, "Download not correct, status [" + status + "] reason [" + reason + "]");            
            return false;
        }   
    }               
    return false;                                   
}

For complete code see : https://github.com/flegare/JAV387_LaboWidget/blob/master/src/com/mobidroid/widgetfact/service/FactService.java

回答2:

A simple way to download your files, See download progress in notification bar and even open your file when it complete to download by just clicking it in the notification bar.

Just call this method and pass your filename and download url

 public void downloadFile(String name, String url){ 
        //download link
        downloadUri = Uri.parse(url);

        DownloadManager.Request request = new DownloadManager.Request(downloadUri);

        //allow download to take place over wifi, mobile network and roaming
        request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE ).setAllowedOverRoaming(true);
        request.setAllowedOverRoaming(false);

        //name to show while downloading
        request.setTitle(name);

        //description to show while downloading
        request.setDescription("Downloading " + name);

        //show on navigation
        request.setVisibleInDownloadsUi(true);

        //download path
        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS.toString(), "/" + name);

        //file open when item on navigation is clicked
        request.allowScanningByMediaScanner();
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
       long downloadId = downloadManager.enqueue(request);

    }

Output

You can learn more here

来源：https://stackoverflow.com/questions/8937817/downloadmanager-action-download-complete-broadcast-receiver-receiving-same-downl