如何从firebase实时数据库中检索列表？

FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference ref = database.getReference();

DatabaseReference usersRef = ref.child("users");

usersRef.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        // 处理检索到的数据
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {
        // 处理取消事件
    }
});

@Override
public void onDataChange(DataSnapshot dataSnapshot) {
    for (DataSnapshot childSnapshot : dataSnapshot.getChildren()) {
        // 处理每个子节点的数据
        String key = childSnapshot.getKey();
        Object value = childSnapshot.getValue();
        // ...
    }
}