Develop Reference

How to get information of an APK file in the file system (not just installed ones) without using File or file-path?

Background
My app (here) can search for APK files throughout the file system (not just of installed apps), showing information about each, allowing to delete, share, install...
As part of the scoped-storage feature on Android Q, Google announced that SAF (storage access framework) will replace the normal storage permissions. This means that even if you will try to use storage permissions, it will only grant to access to specific types of files for File and file-path to be used or completely be sandboxed (written about here).
This means that a lot of frameworks will need to rely on SAF instead of File and file-path.
The problem
One of them is packageManager.getPackageArchiveInfo , which given a file path, returns PackageInfo , which I can get various information about:
name (on the current configuration) , AKA "label", using packageInfo.applicationInfo.loadLabel(packageManager) . This is based on the current configuration of the device (locale, etc...)
package name , using packageInfo.packageName
version code , using packageInfo.versionCode or packageInfo.longVersionCode .
version number , using packageInfo.versionName
app icon, using various ways, based on the current configuration (density etc... ) :
a. BitmapFactory.decodeResource(packageManager.getResourcesForApplication(applicationInfo),packageInfo.applicationInfo.icon, bitmapOptions)
b. if installed, AppCompatResources.getDrawable(createPackageContext(packageInfo.packageName, 0), packageInfo.applicationInfo.icon )
c. ResourcesCompat.getDrawable(packageManager.getResourcesForApplication(applicationInfo), packageInfo.applicationInfo.icon, null)
There are a lot more that it returns you and a lot that are optional, but I think those are the basic details about APK files.
I hope Google will provide a good alternative for this (requested here and here ), because currently I can't find any good solution for it.
What I've tried
It's quite easy to use the Uri that I get from SAF and have an InputStream from it :
#TargetApi(Build.VERSION_CODES.O)
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
setSupportActionBar(toolbar)
packageInstaller = packageManager.packageInstaller
val intent = Intent(Intent.ACTION_OPEN_DOCUMENT)
intent.addCategory(Intent.CATEGORY_OPENABLE)
intent.type = "application/vnd.android.package-archive"
startActivityForResult(intent, 1)
}
override fun onActivityResult(requestCode: Int, resultCode: Int, resultData: Intent?) {
super.onActivityResult(requestCode, resultCode, resultData)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP && requestCode == 1 && resultCode == Activity.RESULT_OK && resultData != null) {
val uri = resultData.data
val isDocumentUri = DocumentFile.isDocumentUri(this, uri)
if (!isDocumentUri)
return
val documentFile = DocumentFile.fromSingleUri(this, uri)
val inputStream = contentResolver.openInputStream(uri)
//TODO do something with what you got above, to parse it as APK file
But now you are stuck because all the framework I've seen needs a File or file-path.
I've tried to find any kind of alternative using the Android framework but I couldn't find any. Not only that, but all libraries I've found don't offer such a thing either.
EDIT: found out that one of the libraries I've looked at (here) - kinda has the option to parse APK file (including its resources) using just a stream, but :
The original code uses a file path (class is ApkFile), and it takes about x10 times more than normal parsing using the Android framework. The reason is probably that it parses everything possible, or close to it. Another way (class is ByteArrayApkFile ) to parse is by using a byte-array that includes the entire APK content. Very wasteful to read the entire file if you need just a small part of it. Plus it might take a lot of memory this way, and as I've tested, indeed it can reach OOM because I have to put the entire APK content into a byte array.
I've found out it sometimes fails to parse APK files that the framework can parse fine (here). Maybe it will soon be fixed.
I tried to extract just the basic parsing of the APK file, and it worked, but it's even worse in terms of speed (here). Took the code from one of the classes (called AbstractApkFile). So out of the file, I get just the manifest file which shouldn't take much memory, and I parse it alone using the library. Here:
AsyncTask.execute {
val packageInfo = packageManager.getPackageInfo(packageName, 0)
val apkFilePath = packageInfo.applicationInfo.publicSourceDir
// I'm using the path only because it's easier this way, but in reality I will have a Uri or inputStream as the input, which is why I use FileInputStream to mimic it.
val zipInputStream = ZipInputStream(FileInputStream(apkFilePath))
while (true) {
val zipEntry = zipInputStream.nextEntry ?: break
if (zipEntry.name.contains("AndroidManifest.xml")) {
Log.d("AppLog", "zipEntry:$zipEntry ${zipEntry.size}")
val bytes = zipInputStream.readBytes()
val xmlTranslator = XmlTranslator()
val resourceTable = ResourceTable()
val locale = Locale.getDefault()
val apkTranslator = ApkMetaTranslator(resourceTable, locale)
val xmlStreamer = CompositeXmlStreamer(xmlTranslator, apkTranslator)
val buffer = ByteBuffer.wrap(bytes)
val binaryXmlParser = BinaryXmlParser(buffer, resourceTable)
binaryXmlParser.locale = locale
binaryXmlParser.xmlStreamer = xmlStreamer
binaryXmlParser.parse()
val apkMeta = apkTranslator.getApkMeta();
Log.d("AppLog", "apkMeta:$apkMeta")
break
}
}
}
So, for now, this is not a good solution, because of how slow it is, and because getting the app name and icon requires me to give the entire APK data, which could lead to OOM. That's unless maybe there is a way to optimize the library's code...
The questions
How can I get an APK information (at least the things I've mentioned in the list) out of an InputStream of an APK file?
If there is no alternative on the normal framework, where can I find such a thing that will allow it? Is there any popular library that offers it for Android?
Note: Of course I could copy the InputStream to a file and then use it, but this is very inefficient as I will have to do it for every file that I find, and I waste space and time in doing so because the files already exist.
EDIT: after finding the workaround (here) to get very basic information about the APK via getPackageArchiveInfo (on "/proc/self/fd/" + fileDescriptor.fd) , I still can't find any way to get app-label and app-icon. Please, if anyone knows how to get those with SAW alone (no storage permission), let me know.
I've set a new bounty about this, hoping someone will find some workaround for this as well.
I'm putting a new bounty because of a new discovery I've found: An app called "Solid Explorer" targets API 29, and yet using SAF it can still show APK information, including app name and icon.
That's even though in the beginning when it first targeted API 29, it didn't show any information about APK files, including the icon and the app name.
Trying out an app called "Addons detector", I couldn't find any special library that this app uses for this purpose, which means it might be possible to do it using the normal framework, without very special tricks.
EDIT: about "Solid Explorer", seems that they just use the special flag of "requestLegacyExternalStorage", so they don't use SAF alone, but the normal framework instead.
So please, if anyone knows how to get app-name and app-icon using SAF alone (and can show it in a working sample), please let me know.
Edit: seems that the APK-parser library can get the app name fine and the icons, but for icons it has a few issues:
the qualifiers are a bit wrong, and you need to find which is the best for your case.
For adaptive icon it can get a PNG instead of VectorDrawable.
For VectorDrawable, it gets just the byte-array. No idea how to convert it to a real VectorDrawable.

OK I think I found a way using the Android framework (someone on reddit gave me this solution), to use file-path and use it, but it's not perfect at all. Some notes:
Not as direct as before.
Good thing is that it might also be possible to handle even files that are outside of the device storage.
It looks like a workaround, and I'm not sure for how long it will work.
For some reason, I can't load the app label (it always returns just the package name instead), and same goes for the app-icon (always null or default icon).
The solution, in short, is using this:
val fileDescriptor = contentResolver.openFileDescriptor(uri, "r") ?: return
val packageArchiveInfo = packageManager.getPackageArchiveInfo("/proc/self/fd/" + fileDescriptor.fd, 0)
I think this same approach can be used for all cases that you need a file-path.
Here's a sample app (also available here) :
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
startActivityForResult(
Intent(Intent.ACTION_OPEN_DOCUMENT).addCategory(Intent.CATEGORY_OPENABLE)
.setType("application/vnd.android.package-archive"), 1
)
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
super.onActivityResult(requestCode, resultCode, data)
try {
val uri = data?.data ?: return
val takeFlags = Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION
contentResolver.takePersistableUriPermission(uri, takeFlags)
val isDocumentUri = DocumentFile.isDocumentUri(this, uri)
if (!isDocumentUri)
return
val documentFile = DocumentFile.fromSingleUri(this, uri) ?: return
val fileDescriptor = contentResolver.openFileDescriptor(uri, "r") ?: return
val packageArchiveInfo = packageManager.getPackageArchiveInfo("/proc/self/fd/" + fileDescriptor.fd, 0)
Log.d("AppLog", "got APK info?${packageArchiveInfo != null}")
if (packageArchiveInfo != null) {
val appLabel = loadAppLabel(packageArchiveInfo.applicationInfo, packageManager)
Log.d("AppLog", "appLabel:$appLabel")
}
} catch (e: Exception) {
e.printStackTrace()
Log.e("AppLog", "failed to get app info: $e")
}
}
fun loadAppLabel(applicationInfo: ApplicationInfo, packageManager: PackageManager): String =
try {
applicationInfo.loadLabel(packageManager).toString()
} catch (e: java.lang.Exception) {
""
}
}
}

Use below code
/**
* Get the apk path of this application.
*
* #param context any context (e.g. an Activity or a Service)
* #return full apk file path, or null if an exception happened (it should not happen)
*/
public static String getApkName(Context context) {
String packageName = context.getPackageName();
PackageManager pm = context.getPackageManager();
try {
ApplicationInfo ai = pm.getApplicationInfo(packageName, 0);
String apk = ai.publicSourceDir;
return apk;
} catch (Throwable x) {
return null;
}
}

Media scanner for secondary storage on Android Q

With the newer Android Q many things changed, especially with scoped storage and gradual deprecation of file:/// URIs. The problem is the lack of documentation on how to handle media files correctly on Android Q devices.
I have a media file (audio) management application and I could not find yet a reliable way to tell to the OS that I performed a change to a file so that it can update its MediaStore record.
Option #1: MediaScannerService
MediaScannerConnection.scanFile(context, new String[]{ filePath }, new String[]{"audio/*"}, new MediaScannerConnection.OnScanCompletedListener() {
#Override
public void onScanCompleted(String s, Uri uri) {
}
});
Works with file:// URIs from primary storage
Not works with file:// URIs from secondary storage (such as removable storage)
Not works with any content:// URI
Option #2: broadcast
context.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, uri));
Not working at all
Soon deprecated
Option #3: manual MediaStore insertion
AudioFileContentValues are some column values from MediaStore.Audio.AudioColumns.
Old method based on file:// URI:
Uri uri = MediaStore.Audio.Media.getContentUriForPath(file_path);
newUri = context.getContentResolver().insert(uri, AudioFileContentValues);
MediaStore.Audio.Media.getContentUriForPath is deprecated
Still not working
Newer method based on what I could put together from documentation:
Uri collection = MediaStore.Audio.Media.getContentUri(correctVolume);
newUri = context.getContentResolver().insert(collection, AudioFileContentValues);
Where correctVolume would be external from primary storage, while it would be something like 0000-0000 for secondary storage, depending on where the file is located.
Insertion returns a content URI such as content://media/external/audio/media/125 but then no record is persisted inside MediaStore for files located in primary storage
Insertion fails with no URI returned and no record in MediaStore
These are more or less all the methods available in previous Android versions but none of them now allow me to notify the system that I changed some audio file metadata and to get Android to update MediaStore records. Event though option #1 is partially working, this could never be a valuable solution because it's clearly not supporting content URIs.
Is there any reliable way to trigger media scan on Android Q, despite where the file is located? We shouldn't even care about file location, according to Google, since we will soon only use content URIs. MediaStore has always been a little frustrating in my opinion, but now the situation is pretty worse.

I'm also currently struggling with that.
I think what you want to do you cannot do any longer once you are on Android Q, because you are not allowed to access the Music directory on Q. You are only allowed to create and access files in directories you created. You did not create the music directory.
Now every change to the Media has to happen threw the MediaStore. So you insert your Music file beforehand and then get an outputstream from the MediaStore to write to it. All the changes on Q on Media should be done threw the MediaStore hence you informing the MediaStore of changes cannot even occur anymore, because you never directly access the File.
This has one giant caviat in that all the new things in MediaStore that make that possible do not exist in older versions of Android. So I do currently believe that you will need to implement everything twice, sadly. At least if you want to actively influences where your music is saved to that is.
Those two MediaStore columns are new in Q and do not exist before Q, witch you'll probably need to use in Q
MediaStore.Audio.Media.RELATIVE_PATH with that you can influence the path where it's saved. So I put "Music/MyAppName/MyLibraryName" there and that will end up saving "song.mp3" into "Music/MyAppName/MyLibraryName/song.mp3"
MediaStore.Audio.Media.IS_PENDING this you should be setting to 1 while the song is still being written and then afterwards you can update it to 0.
I've also now started to implement things twice with if checks for Android versions. It's annoying. I don't want to do it. But it seems like that's the only way.
I'm just gonna put a bit of code here on how I managed inserting music on Android.Q and below. It's not perfect. I have to specify the MIME type for Q, because flacs would now become .flac.mp3 somehow, because it does not quite seem to get that.
So, anyways this is a part that I have updated already to work with Q and before, it downloads a Music file from a music player on my NAS. The app is written in kotlin, not sure if that's a problem for you.
override fun execute(library : Library, remoteApi: RemoteApi, ctx: Context) : Boolean {
var success = false
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
val values = ContentValues().apply {
put(MediaStore.Audio.Media.RELATIVE_PATH, library.rootFolderRelativePath)
put(MediaStore.Audio.Media.DISPLAY_NAME, remoteLibraryEntry.getFilename())
put(MediaStore.Audio.Media.IS_PENDING, 1)
}
val collection = MediaStore.Audio.Media
.getContentUri(MediaStore.VOLUME_EXTERNAL_PRIMARY)
val uri = ctx.contentResolver.insert(collection, values)
ctx.contentResolver.openOutputStream(uri!!).use {
success = remoteApi.downloadMusic(remoteLibraryEntry, it!!)
}
if(success) {
values.clear()
val songId = JDrop.mediaHelper.getSongId(uri)
JDrop.db.music.insert(Music(mediaStoreId = songId, remoteId = remoteLibraryEntry.remoteId, libraryId = library.id))
values.put(MediaStore.Audio.Media.IS_PENDING, 0)
ctx.contentResolver.update(uri, values, null, null)
} else {
ctx.contentResolver.delete(uri, null, null)
}
} else {
val file = File("${library.rootFolderPublicDirectory}/${remoteLibraryEntry.getFilename()}")
if(file.exists()) file.delete()
success = remoteApi.downloadMusic(remoteLibraryEntry, file.outputStream())
if (success) {
MediaScannerConnection.scanFile(ctx, arrayOf(file.path), arrayOf("audio/*")) { _, uri ->
val songId = JDrop.mediaHelper.getSongId(uri)
JDrop.db.music.insert(Music(mediaStoreId = songId, remoteId = remoteLibraryEntry.remoteId, libraryId = library.id))
}
}
}
return success
}
And the MediaStoreHelper Method being this here
fun getSongId(uri : Uri) : Long {
val cursor = resolver.query(uri, arrayOf(Media._ID), null, null, null)
return if(cursor != null && cursor.moveToNext()) {
val idIndex = cursor.getColumnIndex(Media._ID)
val id = cursor.getLong(idIndex)
cursor.close()
id
} else {
cursor?.close()
-1
}
}
One thing when you do not specify the MIME type it seems to assume mp3 is the MIME type. So .flac files would get saved as name.flac.mp3, because it adds the mp3 file type if there is none and it thinks it's a mp3. It does not add another .mp3 for mp3 files. I don't currently have the MIME type anywhere... so I'm gonna go ahead and do this now, I guess.
There is also a helpful google IO talk about scoped/shared storage https://youtu.be/3EtBw5s9iRY
That probably won't answer all of your questions. It sure enough didn't for me. But it was a helpful start to have a rough idea what they even did change to begin with.
For deleting and updating files its kinda the same on Q if you call delete on a mediastore entry, the file will be deleted. Before, Q you have to manually delete the file also. But if you do that on Q your app will crash. So again you have to check wether or not youre on Q or an older version of android and take appropriate actions.

convert Uri to file path but can not open it in nexus 4

I open a picture in album and get the Uri. Then I convert the Uri to a file path. In the log it shows as something like mnt/storage/emulated/0/xxx.jpg. I covert Uri to file path as the way like:
Cursor cursor = GlobalObjectManager.getInstance().getContext().getContentResolver()
.query(filePathUri, null, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
fileName = cursor.getString(column_index);
The problem is that when I open the file with function it catches a FileNotFoundException.
String path = "mnt/storage/emulated/0/xxx.jpg";
FileInputStream in = new FileInputStream(path);
the code works well on other devices with Android 2.3-4.1.
So far as I know is that my Nexus 4 runs Android 4.2 and mnt/storage/emulated/0/ works for multi-user.
In my app I must use FileInputStream() function to read byte data of the beginning of the file.
Could anyone tell me how to fix the bug? Thanks!
ok i fix it. I made a big mistake! I add mnt/ in front of storage/ needlessly, and it takes the bug.

I believe you are seeing /storage/emulated/0. We're seeing this problem too, it seems to be related to the new /storage handling for multiple SD cards, I think it was introduced in Android 4.1 but maybe later. If you look, you'll see that /storage/emulated/0 does not exist on the filesystem, not even as a symlink. Who knows what the system is using that path or what tricks are going on there.
The workaround is to do:
fileName = new File(cursor.getString(column_index)).getCanonicalPath();

I think you should not have the "mnt" ,this is to say,you can code as this:
String path = "mnt/storage/emulated/0/xxx.jpg";
FileInputStream in = new FileInputStream(path);

Retrieve file path from caught DownloadManager intent

Since Android 4.2 if a user downloads some file in the browser the DownloadManager is used. If the user clicks the 'download complete' notification an Intent is and was always launched. Before Android 4.2 the intent used to have the downloaded file's path in the content, such that:
intent.getData()
would return a String such as file:///storage/emulated/0/Download/some_file.ext. However, since Android 4.2 the download manager broadcasts and intent with a content scheme, such as content://downloads/all_downloads/2334.
How do I retrieve the local file path for a downloaded file?
I've tried the following:
public static String getRealPathFromURI(Uri contentUri, Activity activity) {
DownloadManager downloadManager = (DownloadManager) activity.getSystemService(Activity.DOWNLOAD_SERVICE);
String[] contentParts = contentUri.getEncodedPath().split("/");
Cursor q = downloadManager.query(new DownloadManager.Query().setFilterById(Integer.parseInt(contentParts[contentParts.length - 1])));
if (q == null) {
// Download no longer exists
return null;
}
q.moveToFirst();
return q.getString(q.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME));
}
But the cursor never returns any rows (so q.getCount() == 0 and therefor the last return statement throws an exception). Also, the hack by parsing the download file id from the Uri seems odd.
UPDATE: I have also tried:
input = getActivity().getContentResolver().openInputStream(contentUri);
but this returns an error stating
Permission Denial: reading com.android.providers.downloads.DownloadProvider uri content://downloads/all_downloads/2334 from pid=30950, uid=10064 requires android.permission.ACCESS_ALL_DOWNLOADS, or grantUriPermission()
Clearly I can't access the downloads (as my app did not initiate them - the browser did) through the ContentProvider.

Here's what worked. First, you can't (and shouldn't want to) get the file path as botteaap correctly pointed out. (Credits to him for setting me on the right path.) Instead you get a temporary permission automatically to access the file content, using:
InputStream input = getContentResolver().openInputStream(intent.getData());
You can read this InputStream like any other in Java. It seems there is no way to get the file name. If you need a file, first write the input stream to a (temporary) file.
The SecurityException is throw when your temporary access was revoked. This happend for me on some files that I tried to read incorrectly before and specifically when the Intent was picked up in my Acticity's onNewIntent.

Getting it through the content resolver is the right thing. Not every content url is going to be a file. For example, the Gallery app will give you uri's that translate to a network call or a local file depending on the source.
Even if you'd get to the real file path, you'll probably unable to read it, due to file permissions, although you can be lucky it it's on external storage. Have you tried adding android.permission.ACCESS_ALL_DOWNLOADS to your app like the exception suggests? That won't work, since the permission is at signature level :(

I just want to add to the answer from #erickok as it took me several hours to figure this out. As stated by #jcesarmobile, you are only guaranteed to be able to get the name and size of the file, not the full path.
You can get the name and size as follows, and then save to a temp file:
String filename = null;
Long filesize = null;
Cursor cursor = null;
try {
cursor = this.getContentResolver().query(intent.getData(), new String[] {
OpenableColumns.DISPLAY_NAME, OpenableColumns.SIZE}, null, null, null );
if (cursor != null && cursor.moveToFirst()) {
filename = cursor.getString(0);
filesize = cursor.getLong(1);
}
} finally {
if (cursor != null)
cursor.close();
}

Why does File.Exists return false?

I'm querying all images on the Android device as such:
string[] columns = { MediaStore.Images.Media.InterfaceConsts.Data,
MediaStore.Images.Media.InterfaceConsts.Id };
string orderBy = MediaStore.Images.Media.InterfaceConsts.Id;
var imagecursor = ManagedQuery(MediaStore.Images.Media.ExternalContentUri, columns, null, null, orderBy);
for (int i = 0; i < this.Count; i++) {
imagecursor.MoveToPosition(i);
Paths[i]= imagecursor.GetString(dataColumnIndex);
Console.WriteLine(Paths[i]);
Console.WriteLine(System.IO.File.Exists(Paths[i]));
}
The problem is that the output shows that some files don't exist. Here's a sample output:
/storage/sdcard0/Download/On-Yom-Kippur-Jews-choose-different-shoes-VSETQJ6-x-large.jpg
False
/storage/sdcard0/Download/397277_10151250943161341_876027377_n.jpg
False
/storage/sdcard0/Download/Roxy_Cottontail_&_Melo-X_Present..._Some_Bunny_Love's_You.jpg
False
/storage/sdcard0/Download/album-The-Rolling-Stones-Some-Girls.jpg
True
/storage/sdcard0/Download/some-people-ust-dont-appreciate-fashion[1].jpg
True
/storage/sdcard0/Download/express.gif
True
...
/storage/sdcard0/Download/some-joys-are-expressed-better-in-silence.JPG
False
How is this possible? I downloaded these images myself from the internet! They should exist in disk.

You appear to be using a LoaderMananger/ManagedQuery to query the Media Content Provider in Android. A Content Provider is just a way to access a particular SQLite database from different apps. If you use the Android provided Media Content Provider you'll have to update it 'manually' by using MediaScannerConnection to add in the new files that you've placed, as the 'service' may or may not update internally while your app is running.
Here are some related SO questions:
Scan Android SD card for new files
and Trigger mediascanner on specific path (folder), how to? but I don't recommend the answer of globally scanning your SD card.

If this is a Samsung device, all those paths may be incorrect !
// Put this in your code and then log the 'external' string to see
String external = Environment.getExternalStorageDirectory();
if you get say: /storage/sdcard0/
Then Samsung themselves say you have to do this lame append (I claim they broke the API :)
external = external + "/external_sd/";
I am not certain this applies to downloads or not, but I suspect it affects ALL similar sub-paths.
http://developer.samsung.com/forum/board/thread/view.do?boardName=GeneralB&messageId=162934&messageNumber=1381&startId=zzzzz~&searchType=TITLE&searchText=sdcard
[EDIT:] Caveat Emptor ! Even this does not work on some Samsung devices. ARRRRGGGGGG