How can Retrieve data in ListView from Firebase

Question

Can you help me in this problem, I try to display data from in firebase in Listv

Answer 1

public class MainActivity extends AppCompatActivity{
 ListView listView;
    FirebaseDatabase firebaseDatabase;
    DatabaseReference databaseReference;
    ArrayList arrayList = new ArrayList<>();
     ArrayAdapter arrayAdapter;

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

firebaseDatabase = FirebaseDatabase.getInstance();
databaseReference = firebaseDatabase.getReference("Users");


listView = (ListView) findViewById(R.id.lists);

Toast.makeText(this, "ok", Toast.LENGTH_SHORT).show();
databaseReference.addChildEventListener(new ChildEventListener() {
    @Override
    public void onChildAdded(DataSnapshot dataSnapshot, String s) {
        String value=dataSnapshot.getValue(String.class);
        arrayList.add(value);
        arrayAdapter = new ArrayAdapter(MainActivity.this, android.R.layout.simple_list_item_1, arrayList);
        listView.setAdapter(arrayAdapter);

    }

    @Override
    public void onChildChanged(DataSnapshot dataSnapshot, String s) {

    }

    @Override
    public void onChildRemoved(DataSnapshot dataSnapshot) {

    }

    @Override
    public void onChildMoved(DataSnapshot dataSnapshot, String s) {

    }

    @Override
    public void onCancelled(DatabaseError databaseError) {

    }
});

 }}

This listener is actually used for lists, so its not from the listener. Also since the user is not authenticated you need to change the rules in your database to :-

 {
"rules": {
   ".read": "true",
   ".write": "true"
 }
}