Develop Reference

How to create hidden directory in android?

I am working on an application where I have created some directory which I am accessing through my application I want to make that directory hidden for security purpose .Such that the user can access them only within the application does not access them outside the application as like through file manager.
Any help is appreciated.
Don't make it duplicate because I search out all the answer, but no one has worked for me.

Just appending a dot before the folder name will not protect it. It is only invisible to the user. It can still be accessed from apps, including file managers and therefore the user. It's just hidden by most file managers by default.
As you want to hide the files for security purposes, you should use Android's internal storage.
From the official Android developer guide:
You can save files directly on the device's internal storage. By default, files saved to the internal storage are private to your application and other applications cannot access them (nor can the user). When the user uninstalls your application, these files are removed.
Example:
String FILENAME = "hello_file";
String string = "hello world!";
FileOutputStream fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);
fos.write(string.getBytes());
fos.close();
Android developer guide
You could also encrypt your files and store the encryption key in the android Keystore.
Here is a good answer regarding encryption of files in android.
Official guide regarding the Android Keystore.

Be clear "You want to create directory or folder which is not accessible for other application"(Which is your application folder) Or Create Folder any location but it is hide from your
For First Solution is -
public static File saveFileInAppDirectory(Context context,byte[] inpute, String directoryName,String fileName){
File mypath;
File directory = new File(context.getExternalFilesDir(
Environment.DIRECTORY_PICTURES), directoryName);
if (!directory.mkdirs()) {
directory.mkdir();
}
mypath = new File(directory, fileName);
try {
InputStream is = new ByteArrayInputStream(inpute);
FileOutputStream f = new FileOutputStream(mypath);
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = is.read(buffer)) > 0) {
f.write(buffer, 0, len1);
}
f.close();
} catch (Exception e) {
Log.e("SAVE_IMAGE", e.getMessage(), e);
e.printStackTrace();
}
return mypath;
}
It will create Directory of your app folder Path - Android/Data/Data/Your.Package.Name/FolderName/FileName
For second Solution - just change file name
File mypath = new File(directory, "."+fileName);
If you want to achive both than just replace
new File(directory, fileName); with new File(directory, "."+fileName);

just write the directory name followed by a dot(.)
example:
.myDir or .myDir1
so these directories will not be visible through file manager. And while accessing these directories call them using dot(.) only
example:
"/path/to/folder/.myDir/"
same can be done for filename

For Hiding Folder in Android
Name of your folder is MyApplicationFolder then u need to add (.)Dot in front of the folder name like .MyApplicationFolder.
So When the Folder is created then the folder is hidden mode for images,video,etc inside but it will be visible in FileManager.

Create a file in Android with certain permission

I'm developing an Android application I have to implement a function that create a folder with different files.
I wish the files in the folders were hidden, and this point is not a problem, but I want assign certain permission to files, for example I need that files are not readable / writable by user but only from application.
Also I wish the files in the folder were deleted if the application was uninstalled.
This is the code that i use to create hidden folder:
File JSONStorage = new File(Environment.getExternalStorageDirectory(), ".BMA");
if (!JSONStorage.exists()) {
if (!JSONStorage.mkdirs()) {
Log.wtf("log: ", "Failed to create directory");
}
}

From official Android documentation:
String FILENAME = "hello_file";
String string = "hello world!";
FileOutputStream fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);
fos.write(string.getBytes());
fos.close();
This will create file on device internal memory. This file can be read only by application. (Context.MODE_PRIVATE)

Android create Folder and detect it

I want to create a folder to save a copy of an image from gallery
to use it from my Directory
I have tried a lot for how to save the image inside the folder and how to use it back.
The folder must be Private Folder so that only my app can access it.

you can save files directly on the device's internal storage. By default, files saved to the internal storage are private to your application and other applications cannot access them (nor can the user). When the user uninstalls your application, these files are removed. For example:
http://developer.android.com/guide/topics/data/data-storage.html#filesInternal
String FILENAME = "hello_file";
String string = "hello world!";
FileOutputStream fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);
fos.write(string.getBytes());
fos.close();
MODE_PRIVATE will create the file (or replace a file of the same name) and make it private to your application. Other modes available are: MODE_APPEND, MODE_WORLD_READABLE, and MODE_WORLD_WRITEABLE.
it's take from:
How to create private folder in sdcard

You might want to take a look at the getDir() method that does exactly what you wish to accomplish..

Android saving file to SD Card, not internal storage

I know there have been questions about this, but for some reason nothing seems to work for me.
I'm trying to get 2 text files to save to the SD card from my app. It correctly creates the directory and the files, but always to the Internal Storage, never the External Storage. I do have the permissions in place as well in the Manifest.
try {
File sdCard = Environment.getExternalStorageDirectory();
File myFile = new File(sdCard.getAbsolutePath() + "/rlgl");
myFile.mkdir();
// myFile.createNewFile();
String newLine = System.getProperty("line.separator");
File file = new File(myFile, "rlgls.txt");
if(file.exists()) {
} else if (!file.exists()){
FileOutputStream fOut = new FileOutputStream(file);
OutputStreamWriter myOutWriter =
new OutputStreamWriter(fOut);
for (int i = 0; i < 30; i++) {
myOutWriter.append("0.0" + newLine);
}
myOutWriter.close();
fOut.close();
}
} catch (IOException e) {
e.printStackTrace();
}
This is the code that I am using. I've followed directions from other Stackoverflow responses but it never goes to the SD Card. Is there something I'm doing wrong? Also a follow up question is there a way for me to use the above code in order to make the files invisible to the user. They should have no reason to open them. Thanks in advance.

It correctly creates the directory and the files, but always to the Internal Storage, never the External Storage
No, it places them on external storage. What the user sees as internal storage is what the developer sees as external storage. Internal storage is accessed via methods like getFilesDir(). And none of those are removable storage, such as some form of SD card.
Also a follow up question is there a way for me to use the above code in order to make the files invisible to the user. They should have no reason to open them.
Then put them on internal storage.
my app can't read/write from/to the files when there is a "." in front of their names
I find that very difficult to believe. The . prefix makes them not show up by default in some file browsers, but that's it. Users can get to them (if they are on external storage), and apps can get to them (subject to the same rules as any other files, those without a leading .).

How to save images in Android?

I'm very new to Android programming and I was wondering how can I make an app take a picture and save the image to the internal storage of a device, not to the SD card, because not everyone will have an SD card.

You can try saving it as an sqlite blob. This this thread for how to do the storage. Saying "not everyone will have external storage" is a bad excuse: you should handle both cases. If instead you want to implement it as a file (a perfectly good way to do it), you can look up an external storage directory using the Environment.getExternalStorageDir() call to determine a suitable directory in which to store your files. Read the API documentation here and heed the following note:
Note: don't be confused by the word "external" here. This directory can better be thought as media/shared storage. It is a filesystem that can hold a relatively large amount of data and that is shared across all applications (does not enforce permissions). Traditionally this is an SD card, but it may also be implemented as built-in storage in a device that is distinct from the protected internal storage and can be mounted as a filesystem on a computer.

Yes, you can try to save images in sqlite blob fields. It's just a java way: and let the whole world wait :)
It's a good practice to store all your files, cache etc into /Android/data/<package_name>/files/ directory on external storage. External storage is not the only SD cards and you can get external storage path and state by Environment.getExternalStorageDirectory() and Environment.getExternalStorageState() calls (reference). If you are using API 8 or greater, you can use Context.getExternalFilesDir().
If you would like to get user's hate-rays, you can try to store files and folders in the root of external storage.

Perhaps something like this
Bitmap largeBitmap ; // save your Bitmap from data[]
FileOutputStream fileOutputStream = null;
BufferedOutputStream bos = null;
int quality = 100;
String filePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + File.separator + "myImage.jpg"
File mediaFile = new File(filePath);
try {
fileOutputStream = new FileOutputStream(pictureFile);
bos = new BufferedOutputStream(fileOutputStream);
bitmap.compress(CompressFormat.JPEG, quality, bos);
return pictureFile;
} finally {
if (bos != null) {
try {
bos.close();
} catch (IOException e) {
// ignore close error
}
}