Firestore计算数据多少次？

Question

我正在使用Firestore。我只想检查那个文件。但是该文档包含6个数据。我无需阅读即可查看该文档的可用性。

SF  -名称=“ ...”  -data =“ ...”  -bio =“ .....”  -photo =“ ...”  -time =“ ...”  -time2 =“ .....”

6个数据

DocumentReference docRef = db.collection("cities").document("SF");
docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
    @Override
    public void onComplete(@NonNull Task<DocumentSnapshot> task) {
        if (task.isSuccessful()) {
            DocumentSnapshot document = task.getResult();
            if (document.exists()) {


//No 6 data


            } else {

            }
        } else {
            Log.d(TAG, "get failed with ", task.getException());
        }
    }
});