Android: Should I pass in serializable or recreate the object from Bundle?

Question

So I have a Calendar obj which implements serializable by default and I want to pass it in a bundle so the value of it is saved on screen rotation.

Should I pass it as a serializable or extract the values and recreate the obj for efficiency?

bundle.putSerializable("key", calendar);

or

bundle.putInt("dayKey", calendar.get(Calendar.DAY_OF_MONTH));
bundle.putInt("monthKey", calendar.get(Calendar.MONTH));
bundle.putInt("yearKey", calendar.get(Calendar.YEAR));

i will go with putSerializable. i dont know about the efficency, but its easier to implement and to read rather than explode the object into pieces. What if a serializable object have more than 10 attribut — Randyka Yudhistira, Mar 02 '15 at 03:50
I would go with the simplest and least error prone possibility: `bundle.putInt("time", calendar.getTime().getTime());` — Xaver Kapeller, Mar 02 '15 at 05:54

score 2 · Accepted Answer · answered Mar 02 '15 at 03:50

2

Using Serializable is not recommended in Android; use Parcelable instead.

I would guess it depends on the size of the Object and how cumbersome it is to recreate manually.

answered Mar 02 '15 at 03:50

Emmanuel

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Patrick · Answer 2 · 2015-03-02T05:06:17.170

Go with Parcelable over Serializable. If performance matters, Parcelable could be around 10x faster (http://www.developerphil.com/parcelable-vs-serializable/)

Additionally, you can use https://github.com/johncarl81/parceler to avoid generating (and maintaining!) all the boilerplate code that would otherwise exist.

@Parcel
public class Person {
  ...
}

Parcelable parcelable = Parcels.wrap(new Person(..));
Person = Parcels.unwrap(parcelable);

score 0 · Answer 3 · answered Mar 02 '15 at 04:51

Honestly, while Parcelable is definitely the preferred serialization method, I think for this case you're fine just putting it as a Serializable extra. Considering the amount of work that is done recreating the Activity, I think the expense of serializing a Calendar instance would be negligible.

If nothing else, it makes your code more maintainable and succinct.

Arun Kumar · Answer 4 · 2015-03-02T05:55:06.523

onSaveInstanceState method is used for store Activity's state. and it called when activity you rotate the screen or press home button or open new activity from notification bar.
It called after onPause() method.

You can save your custom Object or any primitive data type i.e. called Activities's states as

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);        
    outState.putSerializable(KEY_CALENDAR, cal);        
}

onRestoreInstanceState() method is used for restore your Activities's states.
It called after the onStart() method

You can Activities's state restore like

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);       
    cal = (Calendar) savedInstanceState.getSerializable(KEY_CALENDAR);
}

Here you can use serializable for save Activities's state.

You can also use onCreate() method for restore your saved state because bundle is same deliver in both method onCreate(), onRestoreInstanceState() like

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main); 

    if(savedInstanceState != null) {
        cal = (Calendar) savedInstanceState.getSerializable(KEY_CALENDAR);
    } else {
        cal = Calendar.getInstance();
        cal.setTime(new Date());    
    }
}

Android: Should I pass in serializable or recreate the object from Bundle?

4 Answers4