Android-Expected a List while deserializing, but got a class java.util.HashMap

Question

I want to get all list of restaurants from Firebase in android.

Here is my code:

boolean delivery;
String openTime, closeTime, restaurantName;
long          


        

Answer 1

I know this can be too late, but I wish my answer could help somebody. I know 2 ways to solve this problem. Once I have time I'll update my answer .

#Solution 1

First of all I copy & paste your code. It is not clear for me how did you add data to firebase, but I feel you added data directly to firebase.

so this is My MainActivity code :

public class MainActivity extends AppCompatActivity {


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

        RestaurantModel rm;
        List utils;

        //restaurant 1
        rm = new RestaurantModel();
        rm.closeTime = "12:00am";
        rm.openTime = "12:00pm";
        rm.delivery = true;
        rm.likes = 300;
        rm.restaurantName = "KFC";
        utils = new ArrayList<>();
        utils.add("free wifi");
        utils.add("free Parking");
        utils.add("free water");
        rm.utilities = utils;

        //write first restaurant to Firebase
        rm.addRestaurantToFirebase(rm);


        //restaurant 2
        rm = new RestaurantModel();
        rm.closeTime = "5:00am";
        rm.openTime = "12:00pm";
        rm.delivery = false;
        rm.likes = 500;
        rm.restaurantName = "SubWay";
        utils = new ArrayList<>();
        utils.add("free wifi");
        utils.add("free Parking");

        rm.utilities = utils;

        //write Second restaurant to Firebase
        rm.addRestaurantToFirebase(rm);


        rm.getallRestaurant();

    }

}

and this is RestaurantModel :

public class RestaurantModel {
    public boolean delivery;
    public String openTime;
    public String closeTime;
    public String restaurantName;
    public long likes;
    public List utilities;


    public List listRes;

    DatabaseReference dataResReference;

    public RestaurantModel() {
        dataResReference = FirebaseDatabase.getInstance().getReference().child("restaurants");
    }

    public List getallRestaurant() {
        listRes = new ArrayList<>();

        ValueEventListener valueEventListener = new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                for (DataSnapshot dataValues : dataSnapshot.getChildren()) {
                    RestaurantModel restaurantModel = dataValues.getValue(RestaurantModel.class);
                    listRes.add(restaurantModel);

                    Log.d("restaurantModel", restaurantModel.restaurantName);
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        };
        dataResReference.addListenerForSingleValueEvent(valueEventListener);
        return listRes;
    }


    public void addRestaurantToFirebase(RestaurantModel rm) {
        dataResReference.child(restaurantName).setValue(rm);
    }

}

here the result in firebase