如何在 Node 中從大型 Firebase 資料庫中有效地選擇隨機產品？

<br>ListView listView = (ListView) findViewById(R.id.list_view);<br>ArrayAdapter arrayAdter (context, android.R.layout.simple_list_item_1, randomProductList);<br>listView.setAdapter(arrayAdapter);<br>DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference(); child("products"); // 新增了對.child("products")<br>ValueEventListener valueEventListener = new ValueEventListener() {<br><pre class="brush:php;toolbar:false">@Override
public void onDataChange(DataSnapshot dataSnapshot) {
    List<String> productList = new ArrayList<>();
    for(DataSnapshot ds : dataSnapshot.getChildren()) {
        String name = ds.child("name").getValue(String.class);
        productList.add(name);
    }

    int productListSize = productList.size();
    List<String> randomProductList = new ArrayList<>();

    randomProductList.add(new Random().nextInt(productListSize)); //Add the random product to list
    arrayAdapter.notifyDatasetChanged();
}

@Override
public void onCancelled(DatabaseError databaseError) {
    Log.d(TAG, "Error: ", task.getException()); //Don't ignore errors!
}

<p>Firebase-root-root <br> |<br> --- products<br> | |<br> | ---productIdOne<br> | | |<br> | | --- //詳細資料<br> |<br> | ---productIdTwo<br> | |<br> | --- //詳細資料<br> | <br> --- ProductIds<br></p><pre class="brush:php;toolbar:false">      |
      --- productIdOne: true
      |
      --- productIdTwo: true
      |
      --- //And so on

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();<pre class="brush:php;toolbar:false">@Override
public void onDataChange(DataSnapshot dataSnapshot) {
    List<String> productIdsList = new ArrayList<>();
    for(DataSnapshot ds : dataSnapshot.getChildren()) {
        String productId = ds.getKey();
        productIdsList.add(productId);
    }

    int productListSize = productList.size();
    List<String> randomProductList = new ArrayList<>();

    DatabaseReference productIdRef = rootRef.child("products").child(productIdsList.get(new Random().nextInt(int productListSize));
    ValueEventListener eventListener = new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            String name = dataSnapshot.child("name").getValue(String.class);
            Log.d("TAG", name);
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            Log.d(TAG, "Error: ", task.getException()); //Don't ignore errors!
        }
    };
    productIdRef.addListenerForSingleValueEvent(eventListener);
}

@Override
public void onCancelled(DatabaseError databaseError) {
    Log.d(TAG, "Error: ", task.getException()); //Don't ignore errors!
}