Develop Reference

Android mkdirs() doesn't work

I'm trying to generate a folder with my android application in my phone storage (not on the sdcard) but my mkdirs() is not working.
I have set the android.permission.WRITE_EXTERNAL_STORAGE in my manifest and use this basic code :
File mediaStorageDir = new File(Environment.getExternalStorageDirectory(), "/MyDirName");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("App", "failed to create directory");
}
}
but it doesn't work ... The mkdirs is always at false and the folder is not created.
I have tried everything and looked at all the topics about it but nothing is working and I don't know why.

if you target and compile sdk is higher then lolipop then please refer this link
or
File sourcePath = Environment.getExternalStorageDirectory();
File path = new File(sourcePath + "/" + Constants.DIR_NAME + "/");
path.mkdir();

If you you the emulator and the Device File Explorer of Android Studio, be sure that you right-click over a folder of the emulator and then click on 'synchronize' to update the files displayed. The Device File Explorer doesn't update by itself in real time.

when writing code for android API 29 and above use the following permission in your application manifest (AndroidManifest.xml)
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>
Then in your java file add the following lines of code
`ActivityCompat.requestPermissions(this, new String[]
{
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.WRITE_EXTERNAL_STORAGE
},
PackageManager.PERMISSION_GRANTED);
StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
file = new File(Environment.getExternalStorageDirectory().getPath(), "MyDirName/");
if (!file.exists()) {
try {
file.mkdirs();
} catch (Exception e) {
e.printStackTrace();
}
}
`

Android - MediaStore.Images.Media.insertImage - Unable to create file

I'm experiencing some weird problems related to Media.insertImage method
https://developer.android.com/reference/android/provider/MediaStore.Images.Media.html#insertImage(android.content.ContentResolver,%20android.graphics.Bitmap,%20java.lang.String,%20java.lang.String)
private Uri createTemporaryUri(Bitmap bitmap)
{
fixMediaDirForKitkat();
String savedPath = MediaStore.Images.Media.insertImage(requestTarget.getMyFragment().getActivity().getContentResolver(), bitmap, "someone_tmp", null);
return Uri.parse(savedPath);
}
private void fixMediaDirForKitkat()
{
File sdcard = Environment.getExternalStorageDirectory();
if(sdcard != null) {
File mediaDir = new File(sdcard, "DCIM/Camera");
if( !mediaDir.exists()) {
mediaDir.mkdirs();
}
}
}
For some kitkat devices (4.4 - 4.4.4) without using method fixMediaDirForKitkat insertImage function sometimes returns null. After adding method I'm experiencing:
Caused by java.lang.IllegalStateException: Unable to create new file: /storage/sdcard0/DCIM/Camera/1480524677437.jpg
android.provider.MediaStore$Images$Media.insertImage (MediaStore.java:1008)
some.one.PhotoUploader.createTemporaryUri (PhotoUploader.java:166)
some.one.PhotoUploader.beginImageUpload (PhotoUploader.java:145)
some.one.registration.RegisterFragment.onActivityResult (RegisterFragment.java:107)
Does anything else need to be initialized? Any hack or workaround here is available? Device doesn't have a SD card/space? Unable to create new file tells me nothing ;-)
Any suggestions highly appreciated

If you don't give permission then give permission to your android manifest file and if give ignore it.
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
You want to create directory then follow this code
public static String downloadPath = "/DCIM/Camera";
File fileDir = new File(downloadPath);
if (fileDir.isDirectory()) {
request.setDestinationInExternalPublicDir(downloadPath, filename);
} else {
fileDir.mkdirs();
request.setDestinationInExternalPublicDir(downloadPath, filename);
}
OR
Issue seems it be related with Android Runtime Permission introduced in Android 6.0
When your app targeting API Level 23, by default all the permission is false you have to request permission dialog and approve the permission before using that into your app.

android mkdirs not working

i need to save an image from camera on android.
i used the write external storage permission in manifest and i am using this code
File dir = new File(Environment.getExternalStorageDirectory(), "Test");
if (!dir.exists() || !dir.isDirectory())
dir.mkdirs();
String path = dir.getAbsolutePath();
Log.d(TAG, path); //log show the path
File file = new File(dir.getAbsolutePath() + "/Pic.jpg");
Log.d(TAG, file.getAbsolutePath()); //again path is shown here
outStream = new FileOutputStream(file);
outStream.write(bytes);
outStream.close();
Log.d(TAG, "onPictureTaken - wrote bytes: " + bytes.length); //fail here
} catch (FileNotFoundException e) {
Log.d(TAG, "not done"); //error is here (this exception is thrown)
} catch (IOException e) {
Log.d(TAG, "not");
} finally { }
i also tried mkdir() instead of mkdirs() same result.
any idea what went wrong in the code?
thanks

For those not as experienced like me. I fought this issue, lost hair for some time. I am targeting api 21 (for compatibility sake) and it worked on lollipop but on marshmallow it would not create the directory. I did have the "uses" permission in the manifest but it still would not work. Apparently in Marshmallow when you install with Android studio it never asks you if you should give it permission it just quietly fails, like you denied it. You must go into Settings, apps, select your application and flip the permission switch on.

Some one like me who was trying in Android10. Please use below API in manifest:
<application android:requestLegacyExternalStorage="true" ... >
...
</application>
Latest Update From Google:
After you update your app to target Android 11, the system ignores the requestLegacyExternalStorage flag.

Did you put
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
in your AndroidManifest? If you are using android M you must request user permission to write on sd, look here an example

IDIOT ME! i have used the Manifest Permission but when installed the app on phone i didnt grant permission for storage!... i understand a negative on this question... but i hope if someone else face the same..check your phone permission. sorry all for inconvenience.

you have created directory, not file. Create new file with following code
File file = new File(dir.getAbsolutePath() + "/Pic.jpg");
file.createNewFile()

if you are testing on android M, you should probably check Settings > App > Permission to see if permission to access storage is granted. This saved me.

if you already allowed R/W permission(Runtime Permission too) and still doesn't work add this below mentioned line in your AndroidManifest.xml
<application
........
........
android:requestLegacyExternalStorage="true">
Note: this must required if you'r targeting Android 10+

Starting from API 30 you can only write in your app-specific files
File dir = new File(context.getFilesDir(), "YOUR_DIR");
dir.mkdirs();
or in the external storage of your app Android/data
File dir = new File(myContext.getExternalFilesDir("FolderName"),"YOUR_DIR");
UPDATE
this answer provided another solution https://stackoverflow.com/a/65744517/8195076
UPDATE
another way is to grant this permission in manifest
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE" />
like this answer https://stackoverflow.com/a/66968986/8195076

Try this. Provide runtime permission for marshmallow it is perfectly work in my Application code :
private String getFilename(String strFileName) {
String filepath = Environment.getExternalStorageDirectory().getPath();
File fileBase = new File(filepath, "Test");
if (!fileBase.exists()) {
fileBase.mkdirs();
}
return (file.getAbsolutePath() + "/" + strFileName + file_exts[currentFormat]);
}
new File(getFilename(edt.getText().toString().trim()))

outputFile = new File(apkStorage + "/" + downloadFileName );
//Create Output file in Main File
//Create New File if not present
if (!outputFile.exists()) {
isExternalStorageWritable();
outputFile.getParentFile().mkdirs();
outputFile.createNewFile();
Log.e(TAG, "File Created");
OutputStream fos = new FileOutputStream(outputFile);//Get OutputStream for NewFile Location
InputStream fis = c.getInputStream();//Get InputStream for connection
byte[] buffer = new byte[1024];//Set buffer type
int len1 = 0;//init length
while ((len1 = fis.read(buffer)) >0) {
fos.write(buffer, 0, len1);//Write new file
}
//Close all connection after doing task
fos.close();
fis.close();
I wrote this code for creating a file, but it is not working in android 11

when writing code for android API 29 and above use the following permission in your application manifest (AndroidManifest.xml)
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>
Adjust your code to read like the following
ActivityCompat.requestPermissions(this, new String[]
{
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.WRITE_EXTERNAL_STORAGE
},
PackageManager.PERMISSION_GRANTED);
StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());
file = new File(Environment.getExternalStorageDirectory().getPath(), "TestDirectory/Document/");
if (!file.exists()) {
try {
file.mkdirs();
} catch (Exception e) {
e.printStackTrace();
}
}

Unable to write image to Android SD Card (Permission Denied) [duplicate]

The following code which consists of downloading a file from a server and save it in the storage works fine when the device has an internal storage.
But when I tried it with a device with no internal storage, only with external storage I get the following exception.
java.io.filenotfoundexception open failed eacces (permission denied)
public void downloadFile(String dlUrl, String dlName) {
int count;
HttpURLConnection con = null;
InputStream is = null;
FileOutputStream fos = null;
try {
URL url = new URL( dlUrl );
con = (HttpURLConnection) url.openConnection();
con.setDoInput(true);
con.connect();
is = url.openStream();
String dir = Environment.getExternalStorageDirectory() + Util.DL_DIRECTORY;
File file = new File( dir );
if( !file.exists() ){
file.mkdir();
}
Util.LOG_W(TAG, "Downloading: " + dlName + " ...");
fos = new FileOutputStream(file + "/" + dlName);
byte data[] = new byte[1024];
while( (count = is.read(data)) != -1 ){
fos.write(data, 0, count);
}
Util.LOG_D(TAG, dlName + " Download Complete!");
} catch (Exception e) {
Util.LOG_E(TAG, "DOWNLOAD ERROR = " + e.toString() );
bServiceDownloading = false;
}
finally{
try {
if( is != null)
is.close();
if( fos != null)
fos.close();
if( con != null)
con.disconnect();
} catch (Exception e) {
Util.LOG_E(TAG, "CLOSE ERROR = " + e.toString() );
}
}
}
And in manifest file I has the following:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
Any suggestions what maybe the cause?
By the way Environment.getExternalStorageDirectory() returns /mnt/sdcard/ and file.mkdir() return false.

This attribute is "false" by default on apps targeting
Android 10 or higher.
<application android:requestLegacyExternalStorage="true" ... >
...
</application>

This problem seems to be caused by several factors.
Check#1
First add this permission in your manifest file and check if it is working:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application>
...
</application>
　　.....
Check#2:
If you are running on an emulator, check the properties to see if it has an SD card.
Check#3:
Disable file transfer from device to computer. If Enabled, the app wont be able to access the SD card.
Check#4:
If still not working, try the following:
String dir = Environment.getExternalStorageDirectory().getAbsolutePath()
For me the following worked:
The problem is that getExternalStorageDirectory returns /mnt/sdcard whereas I need the actual path of external storage which is /mnt/sdcard-ext and there is no API in android that can get me the absolute path of removable sdcard.
My solution was to hard code the directory as follows:
String dir = "/mnt/sdcard-ext" ;
Since the application is intended to work only on one device, the above did the job.
If you encounter the same problem, use an file explorer application to find out the name of the external directory and hard code it.

Use READ_EXTERNAL_STORAGE permission to read data from the device.

Did you try it on emulator? Check the properties if it has an SD card. I had the same problem, and it was because the emulator did not have an SD card. Check if yours has or not.

I had the same problem, and i solved it by disabling file transfer from device to computer.
Because if u enable file transfer, sd card is not accessible to debugging application.

try
Environment.getExternalStorageDirectory().getAbsolutePath()
and don't forget to add
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Try using mkdirs instead of mkdir. If you are creating a directory path and parent doesn't exist then you should use mkdirs.

I suspect you are running Android 6.0 Marshmallow (API 23) or later. If this is the case, you must implement runtime permissions before you try to read/write external storage.
https://developer.android.com/training/permissions/requesting.html

i have done very silly mistake.
I have already put in AndroidManifest.xml
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
and also add permission in java file,as get permission pragmatically.
But there is mistake of Manifest.permission.READ_EXTERNAL_STORAGE.
Please use Manifest.permission.WRITE_EXTERNAL_STORAGE.
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, requestCode);

I had the same problem. I used the write and read permission in the manifest correctly , yet it didn't work! The solution was very silly: unplug your phone from the PC before running the application. It seems when your phone is connected as "Mass storage" to the PC, the application cannot access the external storage.

First in your manifest file declare permissions :
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE" />
now in header of application tag of manifest file :
android:requestLegacyExternalStorage="true"
now defines provider for your app in between tag of manifest file. as :
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/provider_path" />
</provider>
now create a folder xml in res folder like this :
now create a xml file provider_path.xml and copy below code in it :
<?xml version="1.0" encoding="utf-8"?>
<path>
<external-path
name="external_files"
path="." />
now in your activity :
String filename = null ;
URL url = null;
try {
url = new URL("http://websitename.com/sample.pdf");
filename = url.getPath();
filename = filename.substring(filename.lastIndexOf('/')+1);
} catch (MalformedURLException e) {
e.printStackTrace();
}
File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)+"/"+filename);
if(file.exists()){
Uri uri = FileProvider.getUriForFile(context, "com.example.www"+".provider",file);
Intent i = new Intent(Intent.ACTION_VIEW);
i.setDataAndType(uri, "application/pdf");
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_GRANT_READ_URI_PERMISSION);
context.startActivity(i);
}
else {
//download file here
new AlertDialog.Builder(context)
.setTitle("Information")
.setMessage("Do you want to download this file ?")
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
})
.setPositiveButton("Continue", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url+""));
request.setTitle(filename);
request.setMimeType("application/pdf");
request.allowScanningByMediaScanner();
request.setAllowedOverMetered(true);
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, filename);
DownloadManager downloadManager = (DownloadManager)context.getSystemService(DOWNLOAD_SERVICE);
downloadManager.enqueue(request);
}
}).show();
}

Android how to create a folder on sd-card?

On my StartActivity, I want to create a Folder for the App on my SD-Card. Now first I set the permission at the manifest.xml like this
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Than I write some code at onCreate Method on my StartActivity like this
//Creat an AppFolder
String appPathString = Environment.getExternalStorageDirectory().getPath() + "/MyIdea";
try {
File appPath = new File(appPathString);
if (!appPath.exists()) {
appPath.mkdirs();
Toast.makeText(getApplicationContext(), "Folder created", Toast.LENGTH_LONG).show();
}
} catch (Exception e) {
Log.e("saveToExternalStorage()", e.getMessage());
}
Now I run the app on my Nexus 5 the app start and the toast is showing. But if I go on my device, I can't find any folder which the name, that is beeing created. What is wrong ?

Try this code. It works for me . You need to point to AbsolutePath of storage
String state;
state = Environment.getExternalStorageState();
if ((Environment.MEDIA_MOUNTED).equals(state)) {
File root = Environment.getExternalStorageDirectory();
File Dir = new File(root.getAbsolutePath() + "/My Ideas");
if (!Dir.exists()) {
Dir.mkdir();
}

I'm just wondering, ( I know, we don't write anything) but please give a try to call appPath.flush(); and appPath.close();
and when I'm adding the WRITE permission, I also adding the READ, just to make sure !
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

After a short search i found, that I need special uses-permissions for android sdk 23. So I change my android
<uses-permission-sdk-23
android:name="android.permission.WRITE_EXTERNAL_STORAGE"
android:maxSdkVersion="23"
/>
Now it works fine. Thanks all for support!