ListView Firebase Android

Conectar una lista con datos almacenados en Firebase

xml del MainActivity:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

 xmlns:app="http://schemas.android.com/apk/res-auto"

 xmlns:tools="http://schemas.android.com/tools"

 android:layout_width="match_parent"

 android:layout_height="match_parent"

 android:orientation="vertical" tools:context=".InformacionActivity">

 <TextView 

android:id="@+id/tnombre" 

android:layout_width="match_parent"

android:layout_height="wrap_content" />

<ListView 

android:id="@+id/list_view_informacion" 

android:layout_width="match_parent" 

android:layout_height="wrap_content" 

android:layout_margin="16dp"> </ListView> 

 </LinearLayout>

Codigo en el MaiActivity:

public class InformacionActivity extends AppCompatActivity { 

private ListView listView;  

private ArrayList<String> arrayList =new ArrayList<>(); 

private TextView tnombre;

public DatabaseReference databaseReference; 

public FirebaseDatabase firebaseDatabase; String nombre;

@Override 

protected void onCreate(Bundle savedInstanceState) { 

super.onCreate(savedInstanceState); 

 setContentView(R.layout.activity_informacion); 

 tnombre=(TextView) findViewById(R.id.tnombre); 

 FirebaseApp.initializeApp(this);

 firebaseDatabase= FirebaseDatabase.getInstance();

 databaseReference= firebaseDatabase.getReference("informacion");

 final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_expandable_list_item_1,arrayList); 

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

 listView.setAdapter(arrayAdapter);

 databaseReference.addChildEventListener(new ChildEventListener() { 

 @Override 

public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) { 

 nombre = dataSnapshot.child("nombre").getValue(String.class); 

 arrayList.add(nombre); arrayAdapter.notifyDataSetChanged(); 

 }

 @Override 

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

 arrayAdapter.notifyDataSetChanged(); 

 } 

 @Override 

public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {

 }

 @Override

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

 } 

 @Override

 public void onCancelled(@NonNull DatabaseError databaseError) {

 } });

 listView.setClickable(true);

 listView.setTextFilterEnabled(true);

 listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

 @Override 

public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 

 String valorInformacion=arrayAdapter.getItem(position); 

 tnombre.setText(valorInformacion); 

 } }); 

}