CODEWITHSUNDEEP
javaandroidfirebasefirebase-realtime-database
JR1232
JR1232

Reputation: 7

Trying to retrieve data from Firebase but getting null

I am trying to retrieve data from my firebase database and print a statement in a text field but I keep getting null values. I'm using the userid to try and get to the child node that I want. My textfield keeps saying "Welcome null logged-in as null" My Firebase Database 

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_welcome);
        final String uid;
        FirebaseUser user;


        user = FirebaseAuth.getInstance().getCurrentUser();
        uid = user.getUid();

        DatabaseReference reference = 
      FirebaseDatabase.getInstance().getReference("User");


         reference.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                fName = dataSnapshot.child(uid).child("fName").getValue(String.class);
                role = dataSnapshot.child(uid).child("role").getValue(String.class);

            }
            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

        welcomeText = (TextView) findViewById(R.id.welcomeText);
        welcomeText.setText("Welcome " + fName + "! You are logged-in as " + role);

Upvotes: 0

Views: 1333

Answers (2)

Md. Asaduzzaman
Md. Asaduzzaman

Reputation: 15423

You should pass your userid as child to get data for only the logged in user. Currently you loop through all the users which gives you wrong data at the end. Try like below:

DatabaseReference reference = 
      FirebaseDatabase.getInstance().getReference("User").child(uid);

instead of 

DatabaseReference reference = 
      FirebaseDatabase.getInstance().getReference("User");

Beside this, Currently you are setting the initial value of fName and role which is null and never update the value with your user detail which you get inside onDataChange. So, update your TextView inside onDataChange. 

@Override
public void onDataChange(DataSnapshot dataSnapshot) {
    fName = dataSnapshot.child("fName").getValue(String.class);
    role = dataSnapshot.child("role").getValue(String.class);

    welcomeText.setText("Welcome " + fName + "! You are logged-in as " + role);
}

Upvotes: 1

Rohit Rawat
Rohit Rawat

Reputation: 453

Move the following lines to the onDataChange() callback method.

welcomeText = (TextView) findViewById(R.id.welcomeText);
welcomeText.setText("Welcome " + fName + "! You are logged-in as " + role);

Upvotes: 1

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