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

Solution 1:

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:

1. Not as direct as before.
2. Good thing is that it might also be possible to handle even files that are outside of the device storage.
3. It looks like a workaround, and I'm not sure for how long it will work.
4. 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) {
                ""
            }
    }
}