Library to create, read, delete, append, encrypt files and more, on internal or external disk spaces with a really simple API.

Many times in our apps, we need to manage files on disk. It can be on external or internal storage. Sometimes we need to create a directory, add files, append text to some file, delete files and even encrypt the data in the files.

In my projects, I found myself reading the same Android doc - Storage Options many times to create the same methods. After a while, I wrote a simple library to be used in my apps. Now, it's the time to share and make it better thanks to you.

• Easy define Internal or External storage
• Create directory
• Create file
• Read file content
• Append content to file
• Delete directory
• Delete file
• Get files
• More options
• Encrypt the file content

1. Clone and import this (Simple Storage) project to your workspace.

2. Add reference from your app to Simple Storage project.

3. Update the manifest.xml of your application and add next line:

   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

You have the next options to initialize the simple storage:

• Prepere to work on External Storage.

   Storage storage = SimpleStorage.getExternalStorage();

• Prepare to work on Internal Storage. In your Activity or Application or any other place where you have Context:

   Storage storage = SimpleStorage.getInternalStorage(mContext);

• You prefer to use External Storage, but if it doesn't exist on the device, then use Internal Storage.

   Storage storage = null;
   if (SimpleStorage.isExternalStorageWritable()) {
   	storage = SimpleStorage.getExternalStorage();
   }
   else {
   	storage = SimpleStorage.getInternalStorage(mContext);
   }

• Create directory under the root path.

   // create directory
   storage.createDirectory("MyDirName");

• Create sub directory.

   // create directory
   storage.createDirectory("MyDirName/MySubDirectory");

• Create directory and override the existing one.

   // create directory
   storage.createDirectory("MyDirName", true);

Create a new file with the content in it.

// create new file
storage.createFile("MyDirName", "fileName", "some content of the file");

The content of the file can be one of the next types:

• String
• byte[]
• Bitmap
• Storable

Read the content of any file to byte array.

byte[] bytes = storage.readFile("MyDirName", "fileName");

Read the content of the file to String.

String content = storage.readTextFile("MyDirName", "my_text.txt");

storage.appendFile("MyDirName", "fileName", "more new data");

You can append:

• String
• byte[]

storage.deleteDirectory("MyDirName");

storage.deleteFile("MyDirName", "fileName");

• Get files in ordered way by: name, date, size

   List<File> files = storage.getFiles("MyDirName", OrderType.DATE);

• Get files and filter by regular expression:

   String regex = ...;
   List<File> files = storage.getFiles("MyDirName", regex);

• Get all nested files (without the directories)

   List<File> files = storage.getNestedFiles("MyDirName");

• Is directory exists

   boolean dirExists = storage.isDirectoryExists("MyDirName");

• Is file exists

   boolean fileExists = storage.isFileExists("MyDirName", "fileName");

You can write and read files while the content is encrypted. It means, that no one can read the data of your files from external or internal storage.

You will continue using the same api as before. The only thing you need to do is to configure the Simple Storage library before the you want to create/read encrypted data.

// set encryption
String IVX = "abcdefghijklmnop"; // 16 lenght - not secret
String SECRET_KEY = "secret1234567890"; // 16 lenght - secret

// build configuratio
SimpleStorageConfiguration configuration = new SimpleStorageConfiguration.Builder()
	.setEncryptContent(IVX, SECRET_KEY)
	.build();
	
// configure the simple storage
SimpleStorage.updateConfiguration(configuration);

Now, you can create a new file with content and the content will be automatically encrypted.
You can read the file and the content will be decrypted.

Example

Create file with next content "this is the secret data":

storage.createFile("MyDirName", "fileName", "this is the secret data");

If we open the file to see it's content then it we will something like this: „f°α�ΤG†_i�ΐp . It looks good :)

And now, read the file data with the same api:

String content = storage.readTextFile("MyDirName", "fileName");

You will see that the content will be: "this is the secret data".

Test project includes android junits. The tests include: create/delete directory, create/read/append file, create/read encrypted file.