Question

I created an instance of a custom class RestaurantList to hold my data (a list of restaurant data received from a web service as json data).

How can I save it in onSaveInstanceState?

Answer 1

Custom objects can be saved inside a Bundle when they implement the interface Parcelable.
Then they can be saved via:

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putParcelable("key", myObject);
    }

Basically the following methods must be implemented in the class file:

 public class MyParcelable implements Parcelable {
     private int mData;

     public int describeContents() {
         return 0;
     }

     /** save object in parcel */
     public void writeToParcel(Parcel out, int flags) {
         out.writeInt(mData);
     }

     public static final Parcelable.Creator<MyParcelable> CREATOR
             = new Parcelable.Creator<MyParcelable>() {
         public MyParcelable createFromParcel(Parcel in) {
             return new MyParcelable(in);
         }

         public MyParcelable[] newArray(int size) {
             return new MyParcelable[size];
         }
     };

     /** recreate object from parcel */
     private MyParcelable(Parcel in) {
         mData = in.readInt();
     }
 }