When I am trying to write into external SDcard from android native code, I am getting permission denied in fopen.
mFp = fopen("/storage/extSdCard/Output/test.txt", "wb");
if I print strerror(errno) it gives ->
fopen(/storage/extSdCard/Output/test.txt) failed: Permission denied
Please note that I have also given the permissions in my Application manifest :
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
....
</manifest>
and also :
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
return true;
}
is returing true.
Please check if the external storage is an external card that is inserted or the sdcard that comes with the device.If it is an sdcard that comes with the device itself try your path as "/mnt/drive_path" and check if you native method is able to write to your storage.
Related
I cannot create new folder any way, it always return false when use mkdirs. I am using Android 6.0.1 in android studio debug mode.
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" android:maxSdkVersion="18" />`
String folder_main = "NewFolder";
Boolean success = false;
File f = new File(Environment.getExternalStorageDirectory(),folder_main
);
if (!f.exists()) {
Log.d("path","not exist");
success=f.mkdirs();
}
else
{
Log.d("path","exist");
}
Log.d("path",success.toString());
I didn't use write permission since in this docs
Starting in API level 19, this permission is not required to
read/write files in your application-specific directories returned by
getExternalFilesDir(String) and getExternalCacheDir().
The doc says you can read/write files only in the directories returned by getExternalFilesDir(String) and getExternalCacheDir() without write permission. But you get directory path by Environment.getExternalStorageDirectory().
Javadoc of Environment.getExternalStorageDirectory() says.
Writing to this path requires the WRITE_EXTERNAL_STORAGE permission, and starting in KITKAT, read access requires the READ_EXTERNAL_STORAGE permission, which is automatically granted if you hold the write permission.
Starting in KITKAT, if your application only needs to store internal data, consider using getExternalFilesDir(String), getExternalCacheDir(), or getExternalMediaDirs(), which require no permissions to read or write.
After countless searching I've managed to find path to my sdcard not the android emulated storage. But when I try to make .txt folder there it ends up with error
/storage/37F0-1515/DCIM/100MEDIA/test.txt: open failed: EACCES (Permission denied)
I don't know why because I have permissions for
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
and also I've enabled the permissions with
if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, request2);
}
Here is the code that I'm using
File sdCard = new File("/storage/37F0-1515/DCIM/100MEDIA");
File dir = new File(sdCard.getAbsolutePath());
if (!dir.exists()) {
dir.mkdirs();
}
final File file = new File(dir, "test" + ".txt");
try {
BufferedWriter bufferedWriter = null;
bufferedWriter = new BufferedWriter(new FileWriter(file));
bufferedWriter.write("test");
bufferedWriter.close();
}
catch(Exception e){Log.v("myApp", e.toString());}
I don't know why android won't let me write to sdcard. Do I need some other permissions ?
I don't know why because I have permissions for
Those permissions are for external storage, not removable storage.
I don't know why android won't let me write to sdcard
You do not have arbitrary filesystem access to removable storage on Android 4.4+.
Try using these methods-
Check if the uses-permission statements are in the right place, they should be below <manifest> and above <application> tags. The correct format -
<manifest>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
...
<application>
...
<activity>
...
</activity>
</application>
</manifest>
Starting from Android Kitkat, there is a new storage policy -
The WRITE_EXTERNAL_STORAGE permission must only grant write access to the primary external storage on a device. Apps must not be allowed to write to secondary external storage devices, except in their package-specific directories as allowed by synthesized permissions. Restricting writes in this way ensures the system can clean up files when applications are uninstalled.
This can however be exploited without rooting(although I have not tried this one), as mentioned here
EDIT -
The above mentioned exploit won't work for Android 5+. There is no standard solution to this problem. Some exploits may be available but they will be device-specific/not reliable/root-access dependent.
However, tools like the Storage Access Framework can be used.
I'm using Samsung J7 Unrooted for Testing,
My AndroidManifest.xml contains the necessary permissions to write to external storage
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
I don't encounter any error when I used the code:
File myFile = new File("sdcard/Billing/mysdfile.txt");
It save the file on the Device Storage.
But when I specify the removable SDCard using the code:
File myFile = new File("/storage/extSdCard/mysdfile.txt");
I encounter the error :
open failed: EACCES (Permission denied)
I've tried different ways to point to the removable SDCard but encountered the same "open failed: EACCES (Permission denied)" error.
I've checked if I have the necessary permissions to write to external storages and it always say "Granted"
public void verifyStoragePermissions() {
if (ContextCompat.checkSelfPermission(InitActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getBaseContext(), "Denied", Toast.LENGTH_SHORT).show();
if (ActivityCompat.shouldShowRequestPermissionRationale(InitActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
} else {
}
}else{
Toast.makeText(getBaseContext(), "Granted",Toast.LENGTH_SHORT).show();
}
}
I've tried almost everything suggested listed in the google search but to no avail. There are a Few who advises to "Root" the phone but that is unfortunately not an option for me...
Hope someone can help me gain the needed permission rights to save files in my removable external storage without resorting to "Rooting" the phone.
i have a piece of code, which creates a file on the /sdcard on the ExternalStorage ("internal" 8GB Memory of a GalaxyTab2 7.0).
directory = new File(Environment.getExternalStorageDirectory(),
"/logs");
directory.mkdirs();
log = new File(directory.getPath() + "/" + this.filename);
boolean created = log.createNewFile();
At the last line i get following error:
... java.io.IOException: open failed: EACCES (Permission denied)
... at java.io.File.createNewFile(File.java:948)
I have
set the permission for writing external storage in the right place in manifest
checked, that the memory is not mounted at pc
checked, that the /logs/ folder hat the correct permissions at file explorer
read every single stackoverflow thread about the topic - nothing worked
Has anyone a hint, which can cause this behavior?
best regards
add below permission in manifest file:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
I used a (self-written) library, which manages all the memory access. This library project has the WRITE_EXTERNAL_STORAGE permission. The App, which references this library must also have this permission, even if it is not directly accessing the storage.
I want to create folder on /mnt/externel1 (which is my external micro-sd card path) but when I create folder problematically [ file.mkdirs() ] it is returning false.
And when I am trying to download a file on that path by creating an outputStream it throwing an exception "Permission denied"
Note: android application not allowing to write on external micro-sd card.
your advise will helpful for me.
Please add below permission in manifest file.
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
you have to mentioned permission in manifest file when you want to write into sdcard.
If you're targeting Honeycomb, you can't write to the external SD card.
Edit
Just noticed the permission stuff - you should make sure that you've got the appropriate permissions. See Chirag Raval's answer.