从Firebase Android中检索随机对象

Question

我希望能够从下图中返回随机对象：

而不仅仅是已经返回的第一个对象（-Kci1vM1dVBYBcPW7QA）。我已经从我的应用程序中插入了当前正在读取的代码。变量1,2和3当前正在读取第一个对象，但我希望它们能够检索随机对象。

public void displayDeals(){

    databaseReference.child("FruitDeals").child("bR4sR4flMkYFrw1SzuWA8hpOnY52").addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {

            deals_information = dataSnapshot.getValue(Deals_Information.class);
            one = deals_information.getDeal();
            two = deals_information.getPrice();
            three = deals_information.getAisleNum();
        }

        @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) {
            throw databaseError.toException();
        }
    });

}