How can I retrieve all nodes data from Firebase to listview in Android?

Question

I've followed below tutorial and it works, but it can only retrieve one spacial node data, how can I retrieve all nodes data? Below photo is my database.

---

DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReferenceFromUrl("my url");
    final FirebaseListAdapter<String> firebaseListAdapter = new FirebaseListAdapter<String>(this, String.class, android.R.layout.simple_list_item_1, databaseReference) {
        @Override
        protected void populateView(View v, String model, int position) {
            TextView textView= (TextView) v.findViewById(android.R.id.text1);
            textView.setText(model);
        }
    };
    listView.setAdapter(firebaseListAdapter);

Answer 1

A FirebaseListAdapter can show a list of items. Your data model is not a list, but a tree. So it cannot be shown with a single FirebaseListAdapter .

Answer 2

I have create Adapter class for binding ListView and row_item.xml for display list of items in ListView .

FireListAdapter.java

public class FireListAdapter extends BaseAdapter {

    private List<User> modelList = new ArrayList<User>();
    private Context context;
    LayoutInflater inflater;

    public FireListAdapter(Context context, List<User> modelList) {
        this.context = context;
        this.modelList = modelList;
        inflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return modelList.size();
    }

    @Override
    public Object getItem(int position) {
        return modelList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View view, ViewGroup parent) {

        view = inflater.inflate(R.layout.row_item, null);

        TextView textName = (TextView) view.findViewById(R.id.textName);
        TextView textEmail = (TextView) view.findViewById(R.id.textEmail);
        textName.setText(modelList.get(position).getName());
        textEmail.setText(modelList.get(position).getEmail());

        return view;
    }
}

And create Welcome.java for display data from FirebaseDatabase in ListView .

    public class Welcome extends AppCompatActivity implements View.OnClickListener {

    private ListView listView;
    private List<User> myModelList = new ArrayList<User>();
    private DatabaseReference mFirebaseDatabase;
    private FirebaseDatabase mFirebaseInstance;
    private String TAG = Welcome.class.getSimpleName();

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.welcome);
        setUI();
        mFirebaseInstance = FirebaseDatabase.getInstance();
        // get reference to 'signUp' node Here signUp is table in FirebaseDatabase 
        mFirebaseDatabase = mFirebaseInstance.getReference("signUp");
        getData();
    }

    public void setUI() {
        textProfile = (TextView) findViewById(R.id.textWelcome);
        listView = (ListView) findViewById(R.id.listItem);
    }

    //This method is getting data from FirebaseDatabase
    public void getData() {
        mFirebaseDatabase.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                Iterable<DataSnapshot> snapshotIterable = dataSnapshot.getChildren();
                Iterator<DataSnapshot> iterator = snapshotIterable.iterator();
                while (iterator.hasNext()) {

                    DataSnapshot dataSnapshot1 = iterator.next();
                    User user = dataSnapshot1.getValue(User.class);
                    user.setName(user.getName());
                    user.setEmail(user.getEmail());
                    myModelList.add(user);
                    FireListAdapter fireListAdapter = new FireListAdapter(Welcome.this, myModelList);
                    fireListAdapter.notifyDataSetChanged();
                    listView.setAdapter(fireListAdapter);
                }
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {
            }
        });
    }
}

Hope this will help You :)