Why does the download manager require "WRITE_EXTERNAL_STORAGE" for maxSdkVersion> 18

Question

I use Download managerto upload a file and save it to external storage as follows:

DownloadManager.Request req = new DownloadManager.Request(uri);
req.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI | DownloadManager.Request.NETWORK_MOBILE)
.setDestinationInExternalFilesDir(TextReaderActivity.this, null, "podcasts/" + Integer.toString(article.id) + PODCAST_EXTENSION);

I get the following exception:

Exception: need WRITE_EXTERNAL_STORAGE permission to use DESTINATION_FILE_URI: uid 10052 does not have android.permission.WRITE_EXTERNAL_STORAGE.

I read that I do not need to ask permission WRITE_EXTERNAL_STORAGEfor maxSdkVersion > 18when writing to external directories, why doesn't it require it here with DownloadManager?

UPDATE:

In Android 4.4 and above, the rules are slightly different:
- to read or write trees embedded in getExternalFilesDir () and getExternalCacheDir () in the directory, you do not need permission
- To write to another location on external storage, you need WRITE_EXTERNAL_STORAGE
- To read from anywhere else on external storage, you need either WRITE_EXTERNAL_STORAGE (if you already have) or READ_EXTERNAL_STORAGE (if not)

Answer 1

The rules that you specify regarding WRITE_EXTERNAL_STORAGErelate to when your process is written to external storage, and then only to your getExternalFilesDir()directories and related ones.

. DownloadManager . DownloadManager — , , , DownloadManager — , , , , API.

Answer 2

doc DownloadManager.Request , , setDestination, WRITE_EXTERNAL_STORAGE: