Develop Reference

This code creating the folder in INTERNAL STORAGE Everytime ,I need to create folder in my SDCARD

Why does this code only create a new folder in the internal storage and not create the folder on the SD Card.
Thanks
Code:
File direct = new File(Environment.getExternalStorageDirectory()+"/Akshay");
if(!direct.exists()) {
if(direct.mkdir()); //directory is created;
}
Manifest:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Try this :
File f = new File(Environment.getExternalStorageDirectory(), 'Akshay');
if (!f.exists()) {
f.mkdirs();
}

How to create folder in external storage?

This is what I tried.
private void createFolderInExternalStorage() {
String storagePath = System.getenv("SECONDARY_STORAGE");
Log.e("storagePath->",storagePath);
String path = "not available";
if (storagePath != null) {
Log.e("Path->", "" + storagePath);
File file = new File(storagePath.toString());
Log.e("readable->", "" + file.canRead());
Log.e("writable->", "" + file.canWrite());
Log.e("executable->", "" + file.canExecute());
dir = new File(storagePath + File.separator+etFolder.getText().toString());
if (!dir.exists()) {
dir.mkdirs();
Toast.makeText(this,"Folder "+etFolder.getText().toString()+" created",Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(this,"Folder "+etFolder.getText().toString()+" already exists",Toast.LENGTH_SHORT).show();
}
path = dir.getPath();
} else {
Toast.makeText(this,"External Storage not available",Toast.LENGTH_SHORT).show();
}
tv.setText("External SDCARD path->" + path);
}
if Secondary storage is present then System.getenv("SECONDARY_STORAGE") return /storage/sdcard1 in my case but getting following:
03-21 12:02:26.827 14155-14155/com.think.teststorage E/readable->: false
03-21 12:02:26.827 14155-14155/com.think.teststorage E/writable->: false
03-21 12:02:26.828 14155-14155/com.think.teststorage E/executable->: false
Even in some devices getting the above status as true but folder creation fails.
I have added the permission:
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
Suggestions are welcome.

You can use this code to create a folder.
File dir = new File("path/of/your/folder");
try{
if(dir.mkdir()) {
System.out.println("Folder created");
} else {
System.out.println("Folder is not created");
}
}catch(Exception e){
e.printStackTrace();
}
Add this permission also :
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
For further reference : see this link
Let me know if this works for you! :)

Use the following lines:
//Define the path you want
String path = Environment.getExternalStoragePublicDirectory(Environment.YOUR_DIRECTORY) + File.separator + "YourFolderName";
File file = new File(path);
if (!file.exists()) {
file.mkdirs();
}
YOUR_DIRECTORY is the directory where you want to create the folder, for example: DIRECTORY_DOCUMENTS, DIRECTORY_DOWNLOADS, DIRECTORY_PICTURES etc.
In your manifest should to add permission for write:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Hope it help!

It is very simple and straightforward in android
`
File mFolder = new File(Environment.getExternalStorageDirectory(), "Folder_Name");
if (!mFolder.exists()) {
mFolder.mkdirs();
mFolder.setExecutable(true);
mFolder.setReadable(true);
mFolder.setWritable(true);
}
`
Also include required permissions in manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Just put these lines of code,
// create a File object for the parent directory
File wallpaperDirectory = new File("/sdcard/Wallpaper/");
// have the object build the directory structure, if needed.
wallpaperDirectory.mkdirs();
// create a File object for the output file
File outputFile = new File(wallpaperDirectory, filename);
// now attach the OutputStream to the file object, instead of a String representation
FileOutputStream fos = new FileOutputStream(outputFile);
and add require permission
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Does not work on KitKat, external, physical sdcard ??
then use use
Environment.getExternalStorageDirectory().getPath();

Delete files from application directory folder in Android?

I created folder inside application directory.
File dir = new File(getActivity().getFilesDir().getParent() + File.separator + "Image directory");
in that again i created folder for specify contents
File dir1 = new File(getActivity().getFilesDir().getParent() + File.separator + "Image directory" + File.separator+ "Image 1");
Inside that I am going to storage images. Images are stored and accessed.
I want to delete all images which are stored at dir1 location.
I tried
if(dir1.isDirectory())
{
for (int j = 0; j < dir1.length; j++)
{
File file = new File(dir1, dir1[j]);
//file.canExecute();
file.delete();
}
}
file.delete(); returns false each time.
I added permissions in manifest
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>

In your file.delete method you have used bundle don't know where did that came from.
Below code will delete all files in your Image Directory
File dir1 = new File(getActivity().getFilesDir().getParent() + File.separator + "Image directory" + File.separator+ "Image 1");
if (dir1 .isDirectory()) {
String[] children = dir1 .list();
for (int i = 0; i < children.length; i++) {
new File(dir1 , children[i]).delete();
}
}
Make sure you have permission for writing in external memory, which you already have
uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"

how to create a folder in android External Storage Directory?

I cannot create a folder in android External Storage Directory.
I have added permissing on manifest,
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Here is my code:
String Path = Environment.getExternalStorageDirectory().getPath().toString()+ "/Shidhin/ShidhiImages";
System.out.println("Path : " +Path );
File FPath = new File(Path);
if (!FPath.exists()) {
if (!FPath.mkdir()) {
System.out.println("***Problem creating Image folder " +Path );
}
}

Do it like this :
String folder_main = "NewFolder";
File f = new File(Environment.getExternalStorageDirectory(), folder_main);
if (!f.exists()) {
f.mkdirs();
}
If you wanna create another folder into that :
File f1 = new File(Environment.getExternalStorageDirectory() + "/" + folder_main, "product1");
if (!f1.exists()) {
f1.mkdirs();
}

The difference between mkdir and mkdirs is that mkdir does not create nonexistent parent directory, while mkdirs does, so if Shidhin does not exist, mkdir will fail. Also, mkdir and mkdirs returns true only if the directory was created. If the directory already exists they return false

getexternalstoragedirectory() is already deprecated. I got the solution it might be helpful for you. (it's a June 2021 solution)
Corresponding To incliding Api 30, Android 11 :
Now, use this commonDocumentDirPath for saving files.
Step: 1
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Step: 2
public static File commonDocumentDirPath(String FolderName){
File dir = null ;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
dir = new File (Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS)+ "/"+FolderName );
} else {
dir = new File(Environment.getExternalStorageDirectory() + "/"+FolderName);
}
return dir ;
}

The use of Environment.getExternalStorageDirectory() now is deprecated since API level 29, the option is using:
Context.getExternalFilesDir().
Example:
void createExternalStoragePrivateFile() {
// Create a path where we will place our private file on external
// storage.
File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
try {
// Very simple code to copy a picture from the application's
// resource into the external file. Note that this code does
// no error checking, and assumes the picture is small (does not
// try to copy it in chunks). Note that if external storage is
// not currently mounted this will silently fail.
InputStream is = getResources().openRawResource(R.drawable.balloons);
OutputStream os = new FileOutputStream(file);
byte[] data = new byte[is.available()];
is.read(data);
os.write(data);
is.close();
os.close();
} catch (IOException e) {
// Unable to create file, likely because external storage is
// not currently mounted.
Log.w("ExternalStorage", "Error writing " + file, e);
}
}
void deleteExternalStoragePrivateFile() {
// Get path for the file on external storage. If external
// storage is not currently mounted this will fail.
File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
file.delete();
}
boolean hasExternalStoragePrivateFile() {
// Get path for the file on external storage. If external
// storage is not currently mounted this will fail.
File file = new File(getExternalFilesDir(null), "DemoFile.jpg");
return file.exists();
}

I can create a folder in android External Storage Directory.
I have added permissing on manifest,
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Here is my code:
String folder_main = "Images";
File outerFolder = new File(Environment.getExternalStorageDirectory(), folder_main);
File inerDire = new File(outerFolder.getAbsoluteFile(), System.currentTimeMillis() + ".jpg");
if (!outerFolder.exists()) {
outerFolder.mkdirs();
}
if (!outerFolder.exists()) {
inerDire.createNewFile();
}
outerFolder.mkdirs(); // This will create a Folder
inerDire.createNewFile(); // This will create File (For E.g .jpg
file)

we can Create Folder or Directory on External storage as :
String myfolder=Environment.getExternalStorageDirectory()+"/"+fname;
File f=new File(myfolder);
if(!f.exists())
if(!f.mkdir()){
Toast.makeText(this, myfolder+" can't be created.", Toast.LENGTH_SHORT).show();
}
else
Toast.makeText(this, myfolder+" can be created.", Toast.LENGTH_SHORT).show();
}
and if we want to create Directory or folder on Internal Memory then we will do :
File folder = getFilesDir();
File f= new File(folder, "doc_download");
f.mkdir();
But make Sure you have given Write External Storage Permission.
And Remember that if you have no external drive then it choose by default to internal parent directory.
I'm Sure it will work .....enjoy code

If you are trying to create a folder inside your app directory in your storage.
Step 1 : Add Permission
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Step 2 : Add the following
private String createFolder(Context context, String folderName) {
//getting app directory
final File externalFileDir = context.getExternalFilesDir(null);
//creating new folder instance
File createdDir = new File(externalFileDir.getAbsoluteFile(),folderName);
if(!createdDir.exists()){
//making new directory if it doesn't exist already
createdDir.mkdir();
}
return finalDir.getAbsolutePath() + "/" + System.currentTimeMillis() + ".txt";
}

This is raw but should be enough to get you going
// create folder external located in Data/comexampl your app file
File folder = getExternalFilesDir("yourfolder");
//create folder Internal
File file = new File(Environment.getExternalStorageDirectory().getPath( ) + "/RICKYH");
if (!file.exists()) {
file.mkdirs();
Toast.makeText(MainActivity.this, "Make Dir", Toast.LENGTH_SHORT).show();
}

Try adding
FPath.mkdirs();
(See http://developer.android.com/reference/java/io/File.html)
and then just save the file as needed to that path, Android OS will create all the directories needed.
You don't need to do the exists checks, just set that flag and save.
(Also see : How to create directory automatically on SD card

I found some another thing too :
I had the same problem recently, and i tryed abow solutions and they did not work...
i did this to solve my problem :
I added this permission to my project manifests file :
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>
(plus READ and WRITE permissions) and my app just worked correctly.

try {
String filename = "SampleFile.txt";
String filepath = "MyFileStorage";
FileInputStream fis = new FileInputStream(myExternalFile);
DataInputStream in = new DataInputStream(fis);
BufferedReader br =
new BufferedReader(new InputStreamReader(in));
String strLine;
while ((strLine = br.readLine()) != null) {
myData = myData + strLine;
}
in.close();
} catch (IOException e) {
e.printStackTrace();
}
inputText.setText(myData);
response.setText("SampleFile.txt data retrieved from External Storage...");
}
});
if (!isExternalStorageAvailable() || isExternalStorageReadOnly()) {
saveButton.setEnabled(false);
}
else {
myExternalFile = new File(getExternalFilesDir(filepath), filename);
}

How to list files in an android directory?

Here's my code so far:
String path = Environment.getExternalStorageDirectory().toString()+"/Pictures";
AssetManager mgr = getAssets();
try {
String list[] = mgr.list(path);
Log.e("FILES", String.valueOf(list.length));
if (list != null)
for (int i=0; i<list.length; ++i)
{
Log.e("FILE:", path +"/"+ list[i]);
}
} catch (IOException e) {
Log.v("List error:", "can't list" + path);
}
Yet while I do have files in that dir, it returns me list.length = 0... any ideas?

In order to access the files, the permissions must be given in the manifest file.
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
Try this:
String path = Environment.getExternalStorageDirectory().toString()+"/Pictures";
Log.d("Files", "Path: " + path);
File directory = new File(path);
File[] files = directory.listFiles();
Log.d("Files", "Size: "+ files.length);
for (int i = 0; i < files.length; i++)
{
Log.d("Files", "FileName:" + files[i].getName());
}

I just discovered that:
new File("/sdcard/").listFiles()
returns null if you do not have:
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
set in your AndroidManifest.xml file.

Well, the AssetManager lists files within the assets folder that is inside of your APK file. So what you're trying to list in your example above is [apk]/assets/sdcard/Pictures.
If you put some pictures within the assets folder inside of your application, and they were in the Pictures directory, you would do mgr.list("/Pictures/").
On the other hand, if you have files on the sdcard that are outside of your APK file, in the Pictures folder, then you would use File as so:
File file = new File(Environment.getExternalStorageDirectory(), "Pictures");
File[] pictures = file.listFiles();
...
for (...)
{
log.e("FILE:", pictures[i].getAbsolutePath());
}
And relevant links from the docs:
File
Asset Manager

In addition to all the answers above:
If you are on Android 6.0+ (API Level 23+) you have to explicitly ask for permission to access external storage. Simply having
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
in your manifest won't be enough. You also have actively request the permission in your activity:
//check for permission
if(ContextCompat.checkSelfPermission(this,
Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_DENIED){
//ask for permission
requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, READ_EXTERNAL_STORAGE_PERMISSION_CODE);
}
I recommend reading this:
http://developer.android.com/training/permissions/requesting.html#perm-request

Updated working method
My minSdkversion is 21, so I'm using ContextCompat.checkSelfPermission() method to grant permissions apart from also adding the <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/> in manifest. Thus, to get rid of the NullPointerException in spite of having files in your targeted directory, grant permissions as follows:-
MainActivity.java
public class MainActivity extends AppCompatActivity {
/*Other variables & constants here*/
private final int READ_EXTERNAL_STORAGE=100;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// ignore the button code
Button btn = (Button) findViewById(R.id.button);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
openWebView();
}
});
/*---------------------------- GRANT PERMISSIONS START-------------------------*/
// Main part to grant permission. Handle other cases of permission denied
// yourself.
if(ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)
ActivityCompat.requestPermissions(this,new String[] {Manifest.permission.READ_EXTERNAL_STORAGE},READ_EXTERNAL_STORAGE);
/*---------------------------- GRANT PERMISSIONS OVER-------------------------*/
}
And the function that list all the files (in MainActivity.java), thanks to #Yury:-
public void getDownloadedFile() {
String path = Environment.getExternalStorageDirectory().toString()+"/Download/";
Log.d("Files", "Path: " + path);
File directory = new File(path);
File[] files = directory.listFiles();
if(directory.canRead() && files!=null) {
Log.d("Files", "Size: " + files.length);
for(File file: files)
Log.d("FILE",file.getName());
}
else
Log.d("Null?", "it is null");
}

Your path is not within the assets folder. Either you enumerate files within the assets folder by means of AssetManager.list() or you enumerate files on your SD card by means of File.list()

Yury's answer needs some elaboration for newer versions of Android.
First, make sure to defined READ_EXTERNAL_STORAGE permission in manifest file.
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
Include the below, for SDK greater than or equals to Android 10(Q).
<application android:requestLegacyExternalStorage="true"...</application>
Now you can list files in a directory.
String path = Environment.getExternalStorageDirectory().toString()+"/Pictures";
Log.d("Files", "Path: " + path);
File directory = new File(path);
File[] files = directory.listFiles();
Log.d("Files", "Size: "+ files.length);
for (int i = 0; i < files.length; i++)
{
Log.d("Files", "FileName:" + files[i].getName());
}

String[] listOfFiles = getActivity().getFilesDir().list();
or
String[] listOfFiles = Environment.getExternalStoragePublicDirectory (Environment.DIRECTORY_DOWNLOADS).list();

Try this:
public class GetAllFilesInDirectory {
public static void main(String[] args) throws IOException {
File dir = new File("dir");
System.out.println("Getting all files in " + dir.getCanonicalPath() + " including those in subdirectories");
List<File> files = (List<File>) FileUtils.listFiles(dir, TrueFileFilter.INSTANCE, TrueFileFilter.INSTANCE);
for (File file : files) {
System.out.println("file: " + file.getCanonicalPath());
}
}
}

There are two things that could be happening:
You are not adding READ_EXTERNAL_STORAGE permission to your AndroidManifest.xml
You are targeting Android 23 and you're not asking for that permission to the user. Go down to Android 22 or ask the user for that permission.

Try these
String appDirectoryName = getResources().getString(R.string.app_name);
File directory = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + getResources().getString(R.string.app_name));
directory.mkdirs();
File[] fList = directory.listFiles();
int a = 1;
for (int x = 0; x < fList.length; x++) {
//txt.setText("You Have Capture " + String.valueOf(a) + " Photos");
a++;
}
//get all the files from a directory
for (File file : fList) {
if (file.isFile()) {
list.add(new ModelClass(file.getName(), file.getAbsolutePath()));
}
}

If you are on Android 10/Q and you did all of the correct things to request access permissions to read external storage and it still doesn't work, it's worth reading this answer:
Android Q (10) ask permission to get access all storage. Scoped storage
I had working code, but me device took it upon itself to update when it was on a network connection (it was usually without a connection.) Once in Android 10, the file access no longer worked. The only easy way to fix it without rewriting the code was to add that extra attribute to the manifest as described. The file access now works as in Android 9 again. YMMV, it probably won't continue to work in future versions.

For the people are still getting NullPointerException when they try to get file list, if you using Android API 29+ then you need to add
<application android:requestLegacyExternalStorage="true"...
in your AndroidManifest.xml file.
Then request for storage permission again.

Simple way to list files in android device in a specific folder
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
IN Kotlin
val fileRoot = Environment.getExternalStorageDirectory()
val yourDir = File(fileRoot, "FOLDER_NAME")
for (f in yourDir.listFiles()!!) {
if (f.isFile){
print(f.name)
}
}
All the file name will be printed with the file extension