public class Calc extends Activity {
    public static final String PREFS_NAME = "MyPrefsFile";
    
    @Override
    protected void onCreate(Bundle state){
       super.onCreate(state);
       . . .
       // Restore preferences
       SecureSharedPreferences settings = new SecureSharedPreferences(this);
       boolean silent = settings.getBoolean("silentMode", false);
       setSilent(silent);
    }
    @Override
    protected void onStop(){
       super.onStop();
      // We need an Editor object to make preference changes.
      // All objects are from android.context.Context
      SecureSharedPreferences settings = new SecureSharedPreferences(this);
      SecureSharedPreferences.Editor editor = settings.edit();
      editor.putBoolean("silentMode", mSilentMode);
      // Commit the edits!
      // editor.commit(); // Autocommit is on by default ;)
    }
}

    public SecureSharedPreferences(Context context);
    public SecureSharedPreferences(Context context, String key);
    public SecureSharedPreferences(Context context, String key, String secureName);

putSerializable(String key, Serializable object)
getSerializable(String key)