在 Firebase 上显示来自实时数据库的数据

Question

I am trying to display data in my database but I'm having a problem doing so. The data I'm trying to display is saved as "total" and it is saved as an int. I have tried saving it as a string and double but still no luck. Ideally, I would like to display the total then display a message if the total is over the value 9. This is what I have so far.

public class Results extends AppCompatActivity {
    private DatabaseReference mDatabase;
    private FirebaseAuth fAuth;
    private Button btn;
    private TextView userR;
    private  TextView num;

private FirebaseUser currentUser;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_results);
    userR = (TextView) findViewById(R.id.userResults);

    btn = (Button) findViewById(R.id.generate);
    fAuth = FirebaseAuth.getInstance();
    currentUser = fAuth.getCurrentUser();

    mDatabase = FirebaseDatabase.getInstance().getReference().child("FAQ");
}

@Override
public void onStart() {
    super.onStart();

    ValueEventListener scoreListener = new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            faqinputs FAQInputs = dataSnapshot.getValue(faqinputs.class);
            userR.setText(FAQInputs.getTotal());
        }

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

        }
    };

    mDatabase.addValueEventListener(scoreListener);
}

}

"total" is saved in a "FAQ" node which is saved under a "User"

The data structure is as follows: This is a screenshot some data stored under set nodes

The below data is the code I used to create the FAQ node.

  private void sendScoreData() {
        String currentUserID = fAuth.getUid();
        faqinputs FAQInputs = new faqinputs(questionOne, questionTwo, questionThree, questionFour, questionFive, questionSix, questionSeven, questionEight, questionNine, questionTen, total);
        mDatabase.child("Users").child(currentUserID).push().child("FAQ").setValue(FAQInputs);


    }

            }

Answer 1

To get the value of the total property, you have to add all node names in your reference, like in the following lines of code:

String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference totalRef = rootRef.child("Users").child(uid).child("-M4YRj8nbobkuKurbHqC").child("FAQ").child("total");
ValueEventListener valueEventListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        int total = dataSnapshot.getValue(Integer.class);
        Log.d("TAG", "total: " + total);
    }

    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {
        Log.d("TAG", databaseError.getMessage()); //Don't ignore errors!
    }
};
totalRef.addListenerForSingleValueEvent(valueEventListener);

The result in the logcat will be:

total: 15

I see the total to be a number, however, if you save it as a String, use this line:

String total = dataSnapshot.getValue(String.class);