java - Firebase Android : Getting data stored in user Id then to the random Push(). getKey() 值

Question

我的上一个问题已关闭并链接到其他一些相同的问题，但没有一个涵盖我的情况，我仍然需要一些帮助。他们链接到的帖子是:

Android: Retrieve data of a specific user from a Firebase database

Retrieving data from Firebase Realtime Database in Android

Retrieve Current User's Data (user_id) Firebase?

然而，我仍在挣扎，希望有人能帮助我。

如您所见，它首先有一个用户 ID，然后有随 secret 钥，然后是我想要获得的两个信息。当我尝试获取信息时，我的应用程序一直崩溃

我目前正在做的代码:onCreate

auth = FirebaseAuth.getInstance();
    user = auth.getCurrentUser();


    databaseReference = FirebaseDatabase.getInstance().getReference();

之后:

  protected void onStart() {
    super.onStart();
    String userID = user.getUid();
    databaseReference.child(userID).child(databaseReference.push().getKey()).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            for (DataSnapshot data : dataSnapshot.getChildren()){
                Author author = data.getValue(Author.class);
                authorList.add(author);
            }
            SavedQuotes savedQuotes = new SavedQuotes(ShowQuotes.this, authorList);
            list.setAdapter(savedQuotes);
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });
}

savedQuotes 类具有以下信息:

public SavedQuotes(Activity activity, List<Author> authorQuotes){
    super(activity, R.layout.activity_saved_quotes, authorQuotes);
    this.activity = activity;
    this.authors = authorQuotes;
}

@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
    LayoutInflater inflater = activity.getLayoutInflater();
    View listView = inflater.inflate(R.layout.activity_saved_quotes, null, true);

    name = listView.findViewById(R.id.name);
    quotes = listView.findViewById(R.id.quote);

    Author author = authors.get(position);
    name.setText(author.getName());
    quotes.setText(author.getQuote());

    return listView;
}

希望你能帮帮我

Answer 1

这里不需要使用databaseReference.push().getKey()。检查以下内容:

databaseReference = FirebaseDatabase.getInstance().getReference();

databaseReference.child(userID).addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
        for (DataSnapshot data : dataSnapshot.getChildren()){
            Author author = data.getValue(Author.class);
            authorList.add(author);
        }

        ...
    }

    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {

    }
});