问如何在Firebase中通过一次查询返回多个项目？

EN

@IgnoreExtraProperties
public class Attraction{
    String name, description1, descrition2;
    //Other variables/keys

    String getName(){
        return this.name;
    }

    void setName(String name){
        this.name = name;
    }

    //Other getter/setter methods
    public Attraction(){}
}

City
---Attraction Name
------Description 1
------Description 2

DatabaseReference ref = databaseReference.child("City").child("London");

List<Attraction> attractions = new ArrayList<>();
ref.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for(DataSnapshot val : dataSnapshot.getChildren()){
            Attraction attraction = val.getValue(Attraction.class);
            attraction.setName(val.getKey()); //This is because the key is the attraction name based on the structure
            attractions.add(attraction));
        }
        //After getting all of them in a list, return them
        return attractions; //use this if you want to return them as a List Object
        return attractions.toArray(new Attraction[attractions.size()]); //use this if you want to return it as an array
    }
    @Override
    public void onCancelled(FirebaseError firebaseError) {

    }
})