Android Question Problem with File Permission

[brodmuehler]

Dear All

I need some help please regarding storing a database file in internal storage of my Android S22. The background is that I have an app that uses an Sqlite database to store data and information. The app reads and writes from and to the database. The Sqlite file should be stored in a folder in the internal storage of my smartphone, not on an additional SD card, which the S22 doesn't have anyway.

I remember that Google changed the permission rules for reading and writing files to the internal storage, but I fail to figure out what I need to do to get the app working. The app worked nice on one of my older phones.

After I installed the app on my new phone and launched it I got the folling failure message:

Logger verbunden mit: samsung SM-S901B
--------- beginning of main
*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
main_activity_create (java line: 575)
java.io.FileNotFoundException: /storage/emulated/0/gliderlog/gliderlog.sqlite: open failed: EPERM (Operation not permitted)
at libcore.io.IoBridge.open(IoBridge.java:574)
at java.io.FileOutputStream.<init>(FileOutputStream.java:236)
at anywheresoftware.b4a.objects.streams.File.OpenOutput(File.java:449)
at anywheresoftware.b4a.objects.streams.File.Copy(File.java:342)
at b4a.gliderlog.main._activity_create(main.java:575)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:213)
at b4a.gliderlog.main.afterFirstLayout(main.java:105)
at b4a.gliderlog.main.access$000(main.java:17)
at b4a.gliderlog.main$WaitForLayout.run(main.java:83)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:226)
at android.os.Looper.loop(Looper.java:313)
at android.app.ActivityThread.main(ActivityThread.java:8751)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1135)
Caused by: android.system.ErrnoException: open failed: EPERM (Operation not permitted)
at libcore.io.Linux.open(Native Method)
at libcore.io.ForwardingOs.open(ForwardingOs.java:563)
at libcore.io.BlockGuardOs.open(BlockGuardOs.java:274)
at libcore.io.ForwardingOs.open(ForwardingOs.java:563)
at android.app.ActivityThread$AndroidOs.open(ActivityThread.java:8611)
at libcore.io.IoBridge.open(IoBridge.java:560)
... 17 more
*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
Error occurred on line: 82 (Main)
java.io.FileNotFoundException: /storage/emulated/0/gliderlog/gliderlog.sqlite: open failed: EPERM (Operation not permitted)
at libcore.io.IoBridge.open(IoBridge.java:574)
at java.io.FileOutputStream.<init>(FileOutputStream.java:236)
at anywheresoftware.b4a.objects.streams.File.OpenOutput(File.java:449)
at anywheresoftware.b4a.objects.streams.File.Copy(File.java:342)
at b4a.gliderlog.main._activity_create(main.java:729)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:351)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
at b4a.gliderlog.main.afterFirstLayout(main.java:105)
at b4a.gliderlog.main.access$000(main.java:17)
at b4a.gliderlog.main$WaitForLayout.run(main.java:83)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:226)
at android.os.Looper.loop(Looper.java:313)
at android.app.ActivityThread.main(ActivityThread.java:8751)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:571)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1135)
Caused by: android.system.ErrnoException: open failed: EPERM (Operation not permitted)
at libcore.io.Linux.open(Native Method)
at libcore.io.ForwardingOs.open(ForwardingOs.java:563)
at libcore.io.BlockGuardOs.open(BlockGuardOs.java:274)
at libcore.io.ForwardingOs.open(ForwardingOs.java:563)
at android.app.ActivityThread$AndroidOs.open(ActivityThread.java:8611)
at libcore.io.IoBridge.open(IoBridge.java:560)
... 21 more
** Activity (main) Resume **

I zipped my project and attached it to this post. My phone is running with Android 12.

If there is anything else I should share please let me know.
I would highly appreciate if someone could help me.
Cheers
René

 

[agraham]

File access is now very limited on Android and you will not be able to access that folder with normal file permissions.

SaveAs - Let the user select a target folder + list of other related methods

B4A + B4i example: https://www.b4x.com/android/forum/threads/b4x-texteditor-save-and-load-external-files.132731/#post-838166 List of classes or libraries that can be used to access secondary storages: ContentChooser (Phone libray) - allows the user to select a resource or file using external...

www.b4x.com

Manage External Storage - access internal external storage >= SDK 30

Google seems intent on dumbing down Android to the point of uselessnes to me. I think of my devices as little computers and I want a proper file system on them, not the limited tortuous things that Google offers and that I don't understand, ContentChooser, FileProvider, ... o_O I'm getting old...

www.b4x.com

 

[brodmuehler]

Dear All

thanks for pointing me in the right direction. I used the runtimepermissions and now it is working. The issue is closed

Cheers
René