无法从firebase firestore检索数据并将其显示在android studio的View Text中

FirebaseFirestore db = FirebaseFirestore.getInstance();

CollectionReference usersRef = db.collection("users");

usersRef.get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<QuerySnapshot> task) {
        if (task.isSuccessful()) {
            StringBuilder data = new StringBuilder();
            for (QueryDocumentSnapshot document : task.getResult()) {
                // 获取每个文档的数据
                String name = document.getString("name");
                int age = document.getLong("age").intValue();
                
                // 将数据添加到StringBuilder中
                data.append("Name: ").append(name).append(", Age: ").append(age).append("\n");
            }
            
            // 将数据显示在TextView中
            TextView textView = findViewById(R.id.textView);
            textView.setText(data.toString());
        } else {
            Log.d(TAG, "Error getting documents: ", task.getException());
        }
    }
});