问题
The problem
If the cache directory is full, trying to execute a simple request will fail without sending the DownloadManager.ACTION_DOWNLOAD_COMPLETE broadcast.
Note: The problem is general but can be mostly reproduced on low-end devices with limited cache (/data/data/com.android.providers.downloads/cache) size.
The code
The receiver is configured correctly, as I'm still getting the broadcast when the operation succeeds and fails for other reasons.
DownloadManager.Request request = new DownloadManager.Request(Uri.parse("http://www.apkmirror.com/wp-content/themes/APKMirror/download.php?id=44753"));
request.setTitle("Facebook");
DownloadManager downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
downloadManager.enqueue(request);
The desired solution
I'm interested in a solution to the specific issue, or more info if you have encountered it as well.
I'm not looking for a solution that will require me to stop using the DownloadManager or add the WRITE_EXTERNAL_STORAGE permission.
Logs
When the cache is getting full and lastly when it can hold no more you can observe the following log entrance (filtered with downloadmanager)
11-08 08:47:06.079 830-14261/? I/DownloadManager: Download 135 starting
11-08 08:47:06.989 830-14261/? W/DownloadManager: Downloads data dir: /data/data/com.android.providers.downloads/cache is running low on space. space available (in bytes): -6994124
11-08 08:47:06.999 830-14261/? I/DownloadManager: discardPurgeableFiles: destination = 2, targetBytes = 10485760
11-08 08:47:06.999 830-14261/? I/DownloadManager: Purged files, freed 0 for 10485760 requested
11-08 08:47:07.309 830-14261/? W/DownloadManager: Aborting request for download 135: not enough free space in the filesystem rooted at: /data/data/com.android.providers.downloads/cache and unable to free any more
11-08 08:47:07.319 830-14261/? I/DownloadManager: Download 135 finished with status INSUFFICIENT_SPACE_ERROR
Here is a DEMO PROJECT that can demonstrate the issue. Remember that the cache directory has to be full by that point (by non-purgeable items, which from my experience basically means, aborted downloads)
回答1:
Since DownloadManager is a system ContentProvider in essence, you can register your own ContentObserver to it, So when the download provider updates, it'll choose to notify the observer in the case of INSUFFICIENT_SPACE.
final DownloadManager downloadManager = (DownloadManager)context.getSystemService(Context.DOWNLOAD_SERVICE);
context.getContentResolver().registerContentObserver(Uri.parse("content://downloads/my_downloads"),
true, new ContentObserver(null) {
@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
Cursor localCursor = downloadManager.query(
new DownloadManager.Query());
if (localCursor.getCount() == 0) {
localCursor.close();
}
localCursor.moveToFirst();
do {
if ((localCursor.getInt(localCursor.getColumnIndex(DownloadManager.COLUMN_STATUS)) & DownloadManager.STATUS_FAILED )!=0) {
// Download failed, go see why
if (localCursor.getInt(localCursor.getColumnIndex(DownloadManager.COLUMN_REASON)) == DownloadManager.ERROR_INSUFFICIENT_SPACE){
Log.w("DownloadStatus", " Download failed with ERROR_INSUFFICIENT_SPACE");
}
}
}while (localCursor.moveToNext());
}
});
Note that don't set query filter with status DownloadManager.STATUS_FAILED, as DownloadManager weirdly only consider status between 400 and 600 to be failed status, but INSUFFICIENT_SPACE has error code 198...
android.app.DownloadManager.Request:
Cursor runQuery(ContentResolver resolver, String[] projection, Uri baseUri) {
.....
if ((mStatusFlags & STATUS_FAILED) != 0) {
parts.add("(" + statusClause(">=", 400)
+ " AND " + statusClause("<", 600) + ")");
}
}
回答2:
You can receive INSUFFICIENT_SPACE_ERROR broadcast by getting reason of DownloadManager.STATUS_FAILED by following code
private void DownloadStatus(Cursor cursor, long DownloadId){
//column for download status
int columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS);
int status = cursor.getInt(columnIndex);
//column for reason code if the download failed or paused
int columnReason = cursor.getColumnIndex(DownloadManager.COLUMN_REASON);
int reason = cursor.getInt(columnReason);
//get the download filename
int filenameIndex = cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME);
String filename = cursor.getString(filenameIndex);
String statusText = "";
String reasonText = "";
switch(status){
case DownloadManager.STATUS_FAILED:
statusText = "STATUS_FAILED";
switch(reason){
case DownloadManager.ERROR_CANNOT_RESUME:
reasonText = "ERROR_CANNOT_RESUME";
break;
case DownloadManager.ERROR_DEVICE_NOT_FOUND:
reasonText = "ERROR_DEVICE_NOT_FOUND";
break;
case DownloadManager.ERROR_FILE_ALREADY_EXISTS:
reasonText = "ERROR_FILE_ALREADY_EXISTS";
break;
case DownloadManager.ERROR_FILE_ERROR:
reasonText = "ERROR_FILE_ERROR";
break;
case DownloadManager.ERROR_HTTP_DATA_ERROR:
reasonText = "ERROR_HTTP_DATA_ERROR";
break;
case DownloadManager.ERROR_INSUFFICIENT_SPACE:
reasonText = "ERROR_INSUFFICIENT_SPACE";
break;
case DownloadManager.ERROR_TOO_MANY_REDIRECTS:
reasonText = "ERROR_TOO_MANY_REDIRECTS";
break;
case DownloadManager.ERROR_UNHANDLED_HTTP_CODE:
reasonText = "ERROR_UNHANDLED_HTTP_CODE";
break;
case DownloadManager.ERROR_UNKNOWN:
reasonText = "ERROR_UNKNOWN";
break;
}
break;
case DownloadManager.STATUS_PAUSED:
statusText = "STATUS_PAUSED";
switch(reason){
case DownloadManager.PAUSED_QUEUED_FOR_WIFI:
reasonText = "PAUSED_QUEUED_FOR_WIFI";
break;
case DownloadManager.PAUSED_UNKNOWN:
reasonText = "PAUSED_UNKNOWN";
break;
case DownloadManager.PAUSED_WAITING_FOR_NETWORK:
reasonText = "PAUSED_WAITING_FOR_NETWORK";
break;
case DownloadManager.PAUSED_WAITING_TO_RETRY:
reasonText = "PAUSED_WAITING_TO_RETRY";
break;
}
break;
case DownloadManager.STATUS_PENDING:
statusText = "STATUS_PENDING";
break;
case DownloadManager.STATUS_RUNNING:
statusText = "STATUS_RUNNING";
break;
case DownloadManager.STATUS_SUCCESSFUL:
statusText = "STATUS_SUCCESSFUL";
reasonText = "Filename:\n" + filename;
break;
}
}
回答3:
I think Gracie solution needs some improvements like unregistering and checking downloads ids.
If you don't use any restriction for the request you can try to check file size after enqueuing - its not perfect solution:
private static void checkFileSize(Context context, DownloadManager downloadManager, long myDownloadReference, DownloadInfo downloadInfo) {
DownloadManager.Query query = new DownloadManager.Query();
query.setFilterById(myDownloadReference);
Handler handler = new Handler();
handler.postDelayed(() -> {
Cursor cursor = downloadManager.query(query);
if (!cursor.moveToFirst()) {
KLog.i("download list is empty");
return;
}
int size = cursor.getInt(cursor
.getColumnIndex(DownloadManager.COLUMN_TOTAL_SIZE_BYTES));
int status = cursor.getInt(cursor
.getColumnIndex(DownloadManager.COLUMN_STATUS));
int reason = cursor.getInt(cursor
.getColumnIndex(DownloadManager.COLUMN_REASON));
cursor.close();
if (reason == DownloadManager.ERROR_INSUFFICIENT_SPACE)
DownloadedReceiver.handleInsufficientSpace(context, downloadInfo);
}, 1500);
}
来源：https://stackoverflow.com/questions/33595541/downloadmanager-doesnt-send-broadcast-after-insufficient-space-error