Develop Reference

How to create folder in root of storage Android

I'm new at this.
Telegram, Whatsapp, Vk, Aliexpress - All this apps can write they folders in /Storage/emulated/0
How can I create my folder in this place for Android 5...10?
When I try to use File("/storage/emulated/0/", myfile) - it doesn't work.
Please, can anyone give some mini example how can I create my files in storage

Since you haven't written any code, I can't tell you what you're doing wrong. But this is something that might help you.

First you need to declare permissions on your manifest.
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
After that you can simply use this to create your folder.
String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/" +
"folderName";
File directory = new File(path);
directory.mkdirs(); // It returns a boolean you can use it to check if your folder
// was created.

Yes, You can create Folders inside the External Storage too.
But, keep in mind that you cannot use emulated/0 because it is different for different devices.
File path = new
File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/Folder/");
if(!path.exists()){
boolean k = path.mkdirs();
}
Although, Environment.getExternalStorageDirectory() is deprecated as of API29. So You can use getExternalDir() too.

Create a file folder for app

The below code doesn't create a folder in my device.
String intStorageDirectory = context.getFilesDir().toString();
File folder = new File(intStorageDirectory, "test");
folder.createNewFile();;
I need a folder created for my app to store media, when user installs it. That folder should be visible on file explorer. How can i do it?

With the current snippet you created a file, you can also create folder by creating file but your current directory is the base folder, getFilesDir() points internal storage for your app which not visible nor accessible unless explicitly declared. You can create a folder and file by creating with new File().createNewFile() or create only folder using mkdirs() but you won't be able to display it using a file explorer app and that folder and files inside it will be deleted when/if user uninstalls your app.
To save files externally(This doesn't mean saving to SD Card) you can create directory and file with
File mediaStorageDir = new File(Environment.getExternalStorageDirectory(), folderName);
if (!mediaStorageDir.exists()) {
mediaStorageDir.mkdirs()
}
File mediaFile = new File(mediaStorageDir.getAbsolutePath() + File.separator + fileName);
And you need some kind of OutputStream to write data to that file.
Make sure that you ask <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> inside your AndroidManifest.xml file and ask write permission on runtime if your android:targetSdkVersion="23" or above

new File(context.getFielsDir(), "test").mkdirs();
createNewFile creates a file, not a folder. Using mkdirs instead of mkdir ensures that all parents exist. There's also no reason to go through a string when you already have a File.

Adding folder.mkdirs(); should work in place of folder.createNewFile(); And don't forget to add the permissions.
This will create a folder in you data directory.
And just a suggestion , if you want to store media in a SD card folder maybe Environment.getExternalStorageDirectory() is good.

create visible folder sdcard, Android

I'm developping an application where I need to create new folders/files in the sdcard. The thing is I can see them using a root explorer but not with the default one which comes with Android.
I've taken a look at several similar questions here but don't seem to work for me.
For sure, I'm using in my manifest this:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
and I'm writing all the Files using:
String path = Environment.getExternalStorageDirectory() + "/FolderName/FileName.format"
but as I said, these new folders/files remained hidden and can only be seen using a root explorer. Neither the folder nor file name starts with "."
Thanks in advance.

Try using mkDirs()
File dir = new File(fullPath);
if (!dir.exists()) {
dir.mkdirs();
}

creating folder in android emulator

I am developing an android application. I need to create a folder in the internal memory, but when I try to create the folder I get the error below. I am running in an emulator.
mkdir failed for /mnt/New Folder , read only file system
I have tried many paths, but still the error persists. The only folder that I am able to create is called "cache", but I cannot browse it by my file chooser activity.
Any idea where is the suitable place to create folders without any permissions?

You can achieve it by this from a Context object (like Activity).
File files_folder = getFilesDir();
File files_child = new File(files_folder, "files_child");
files_child.mkdirs();
File created_folder = getDir("custom", MODE_PRIVATE);
File f1_child = new File(created_folder, "custom_child");
f1_child.mkdirs();
The function
getFilesDir()
will get the folder data/data/yourpackagename/files in internal memory. And the function
getDir("custom", MODE_PRIVATE)
will create a folder name app_custom in your app internal folder.
Answered by Minhtdh

I guess what you call internal memory is atualy the external memory (which can be open by
file chooser activity, the real internal memory only can be open if you have rooted)
If that true, you should chek those belows:
- first, you will need the write storeage permission in Manisfest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
- then you should use `
String path =
Environment.getExternalStorageDirectory().getAbsolutePath() +
"/yourfoldername"
`
than
mnt/yourfoldername
at last you should use mkdirs to create folder than mkdir

How to create a file in an SDCARD directory

I want to create a file(not created) in a directory(not created) in the SDCARD.
How doing it ?
Thank you.

Try the following example:
if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
//handle case of no SDCARD present
} else {
String dir = Environment.getExternalStorageDirectory()+File.separator+"myDirectory";
//create folder
File folder = new File(dir); //folder name
folder.mkdirs();
//create file
File file = new File(dir, "filename.extension");
}
Don't forget to add the permission to your AndroidManifest:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

The problem is that mkdirs() is called on a File object containing the whole path up to the actual file. It should be called on a File object containing the Path (the directory) and only that. Then you should use another File object to create the actual file.

You should also have to add permission to write to external media.
Add following line in the application manifest file, somewhere between <manifest> tags, but not inside <application> tag:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Use This:
DocumentFile tempDir = DocumentFile.fromSingleUri(context,targetDirectoryUri);
DocumentFile newDocumentFile = tempDir.createFile(type,name);
"targetDirectoryUri" is uri of the directory you want to put the file into it.
This is the only solution!
After Api 19 you can not write on SDCard, so you must use DocumentFile
instead File.
In addition, you must also take SDCard permission. To learn how to do this and get the targetDirectoryUri, please read this.

You can use in Kotlin
val file = File( this.getExternalFilesDir(null)?.getAbsolutePath(),"/your_image_path")
if (!file.exists()) {
file.mkdir()
}
Don't forget to give permission
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

See here why creating files on root of the SD card is a bad idea