MA DHARSH.pptx

STORING LOCAL DATA IN
ANDROID
DHARSHINI B
20CS1H4204

INTRODUCTION
• Storing local data in an Android application involves saving
data on the device's local storage, which can be accessed
and manipulated by the application. Local data can be any
type of data, such as user preferences, settings, cached data,
media files, and more.

WAYS TO STORE LOCAL DATA IN ANDROID
• Shared Preferences
• Internal storage
• External storage
• SQLite databases

Internal storage
In Android, you can store data in internal storage using the file system APIs.
Internal storage is private to your app and is not accessible to other apps or
users. Here are the steps to store data in internal storage:
• Get a reference to the internal storage directory for your app using the
getFilesDir() method:
File directory = context.getFilesDir();
• Create a File object to represent the file you want to store:
File file = new File(directory, "myfile.txt");

• Write data to the file using a FileOutputStream. You can use a
BufferedWriter to write strings to the file:
try {
FileOutputStream fos = new FileOutputStream(file);
BufferedWriter writer = new BufferedWriter(new
OutputStreamWriter(fos));
writer.write("Hello world!");
writer.close();
} catch (IOException e) {
e.printStackTrace();
}

• To read data from the file, create a FileInputStream and read the contents into a
byte array. You can use a BufferedReader to read strings from the file:
try {
FileInputStream fis = new FileInputStream(file);
BufferedReader reader = new BufferedReader(new InputStreamReader(fis));
String line = reader.readLine();
reader.close();
}

EXTERNAL STORAGE
In Android, you can store local data in an external file using the file
system APIs. Here are the steps you can follow:
• Add the WRITE_EXTERNAL_STORAGE permission to your app's
AndroidManifest.xml file. This permission allows your app to write to
external storage.
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

• Check for the permission at runtime, since devices running Android
6.0 or later require the user to grant permission at runtime.
if (ContextCompat.checkSelfPermission(context,
Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(activity,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
}

• Create a File object representing the file to write to. You can use the
Environment.getExternalStorageDirectory() method to get the root
directory of the external storage. Then, append the file path to it.
File file = new File(Environment.getExternalStorageDirectory(),
"file.txt");

• Write data to the file using a FileOutputStream.
try {
FileOutputStream fos = new FileOutputStream(file);
fos.write(data.getBytes());
fos.close();
}

• To read data from the file, create a FileInputStream and read the contents
into a byte array.
try {
FileInputStream fis = new FileInputStream(file);
byte[] data = new byte[(int) file.length()];
fis.read(data);
fis.close();
String content = new String(data, "UTF-8");
}

MA DHARSH.pptx

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