saving ArrayList in the bundle

Question

This question has been asked before but I didnt find the answer helpful to my specific case.

I'm populating the ArrayList parts from another activity the first time I access the class but I keep losing the parts instance when I try to access it after the initial creation of it. Every time Task is called parts is empty and I'm not sure how to keep it filled with the details I want it filled with.

public class Task extends ListActivity{
    private PartAdapter partsArrayAdapter;
    ArrayList<Parts> parts ;//= new ArrayList<>()

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (savedInstanceState != null){
            parts = (ArrayList<Parts>)savedInstanceState.getSerializable("parts");
        }
        else {
            try {
            // Get the Bundle Object
            Bundle bundleObject = getIntent().getExtras();

            // Get ArrayList Bundle
            parts = (ArrayList<Parts>) bundleObject.getSerializable("parts");


            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        setContentView(R.layout.activity_parts_list);

        partsArrayAdapter = new PartAdapter(this,parts);
        setListAdapter(partsArrayAdapter);
    }

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

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState){
        super.onRestoreInstanceState(savedInstanceState);
        parts = (ArrayList<Parts>)savedInstanceState.getSerializable("parts");
    }
}