How to Access SharedPreferences in an AsyncTask in Android?

What is the proper way to retrieve SharedPreferences within an AsyncTask in an Android application?

SharedPreferences sharedPreferences = context.getSharedPreferences("my_prefs", Context.MODE_PRIVATE);

Accessing SharedPreferences in an AsyncTask can be tricky due to context management and threading. Here’s how to do it correctly.

class MyAsyncTask extends AsyncTask<Void, Void, String> {
    private Context context;

    public MyAsyncTask(Context context) {
        this.context = context.getApplicationContext();
    }

    @Override
    protected String doInBackground(Void... voids) {
        SharedPreferences sharedPreferences = context.getSharedPreferences("my_prefs", Context.MODE_PRIVATE);
        return sharedPreferences.getString("key", "default");
    }
}

Causes

• Misunderstanding the lifecycle and context in AsyncTask.
• Using an incorrect context reference leading to memory leaks.

Solutions

• Pass the application context to AsyncTask to avoid memory leaks.
• Initialize SharedPreferences in the doInBackground() method.

Mistake: Using an Activity context instead of the Application context.

Solution: Ensure to use context.getApplicationContext() when initializing AsyncTask.

Mistake: Initializing SharedPreferences in the constructor instead of doInBackground().

Solution: Always perform data retrieval or processing in the doInBackground() method.