What is the most suitable way to store object in android?

Question

Hello in my app I need to store single object with several fields. At this moment it is saved like this

@Override
    public Object onRetainNonConfigurationInstance() {
        return UILApplication.advert;
    }

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Advert retainedAdvert = (Advert) getLastNonConfigurationInstance();
        if (retainedAdvert != null) {
            UILApplication.advert = retainedAdvert;
        }
}

Where UILApplication is singleton to keep advert. Sometimes ( often when call camera) advert object is erised to default. So i want to know about save and efficient way to kepp this object. Is it wise to store it in file/ serialise it or create database for a single record or there is something better?

score 1 · Answer 1 · answered Oct 25 '13 at 19:51

Depends how big your object is. Try with shared preferences: http://developer.android.com/guide/topics/data/data-storage.html#pref

Combination of preferences, right places to populate/read from it, and some static init method could do things for you.

Hope it helps.

score 1 · Accepted Answer · edited Oct 25 '13 at 20:14

Taken from my calculator:

@SuppressWarnings("unchecked")
private void loadState() {
    ObjectInputStream ois;
    try {
        ois = new ObjectInputStream(openFileInput(FILE_STATE));
        state = ((State) ois.readObject());
        ois.close();

        ois = new ObjectInputStream(openFileInput(FILE_HISTORY));
        historyListAdapter.setItems((List<String>) ois.readObject());
        ois.close();

    } catch (FileNotFoundException e) {
        e.printStackTrace();
        state = new State();
    } catch (IOException e) {
        e.printStackTrace();
        state = new State();
    } catch (ClassNotFoundException e) {
        Toast t = Toast.makeText(this, "Error parsing saved state",
                Toast.LENGTH_SHORT);
        t.show();
        state = new State();
    }
    setState(state);
}

private void saveState() {
    ObjectOutputStream oos;
    try {
        oos = new ObjectOutputStream(openFileOutput(FILE_STATE,
                Context.MODE_PRIVATE));
        oos.writeObject(state);
        oos.close();

        oos = new ObjectOutputStream(openFileOutput(FILE_HISTORY,
                Context.MODE_PRIVATE));
        oos.writeObject(historyListAdapter.getItems());
        oos.close();

    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

@Override
protected void onPause() {
    saveState();
    super.onPause();
}

Call loadState() in onCreate().

Worked fine for me, I know its not advised to use java serialization in android, but I didn't encounter any errors or bugs whatsoever. No issues with performance either.

You should of course tweak error handling depending on your application.

What is the most suitable way to store object in android?

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