CODEWITHSUNDEEP
javafirebasefirebase-realtime-database
Darin Beaudreau
Darin Beaudreau

Reputation: 391

Cannot seem to write custom object to Firebase database?

I'm working on a project using Firebase, which I've never used before, and I know almost nothing about Firebase itself, as the rest of my team has been responsible for most of the dealings with it. I'm writing a parser for some Excel data where I need to extract some specific data and then upload it to Firebase. The parsing is done, but I'm having trouble writing it to Firebase.

We have a sub-database called "families" in our root database that I need to write this data to. I have a class called RegistrationSheet which contains all the data in this particular spreadsheet broken up into objects to represent the structure of the JSON. I'm aware that you can write custom objects to the Firebase database and it will be converted to a JSON format that represents that data. I found a page detailing the different data types that can be written to the database and converted to JSON, and among them were Map and List. So here are my classes that represent the "families" database.

RegistrationSheet.java:

public class RegistrationSheet {
    public List<Object> families;
    public void addFamily(Family f) { families.add(f); }

    public RegistrationSheet() {
        families = new ArrayList<>();
    }

    public void writeToFirebase() {
        DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("families");
        ref.removeValue(); // Delete the data currently in the database so we can rewrite it.
        ref.setValue(families);
    }

    public File outputJSON() {
        return null;
    }
}

Family.java:

public class Family {
    public Map<String, Object> fields;
    public void addField(String str, Object obj) { fields.put(str, obj); }

    public Family() {
        fields = new HashMap<>();
    }
}

Child.java:

public class Child {
    public Map<String, Object> fields;
    public void addField(String str, Object obj) { fields.put(str, obj); }

    public Child() {
        fields = new HashMap<>();
    }
}

The families list contains Family objects, and one of the "fields" that can be added to the Map in the Family objects is a List of Child objects. I figured that because these are all objects that are valid to write to Firebase, that simply writing the "families" list in the RegistrationSheet object would be enough:

public void writeToFirebase() {
    DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("families");
    ref.removeValue(); // Delete the data currently in the database so we can rewrite it.
    ref.setValue(families);
}

Is there something wrong with the structure of any of my classes or how I'm writing the data to Firebase? Because after executing this, the "families" sub-database disappears from Firebase and I have to restore it from my backup. It seems I have the correct DatabaseReference since removeValue() seems to be removing it, but why isn't it then writing the data from the families list?

I would appreciate any help that someone could provide.

Upvotes: 0

Views: 957

Answers (1)

Siddharth Venu
Siddharth Venu

Reputation: 1388

Try the following code. It gives you the reason as to why it is not writing the value.

public void writeToFirebase() {
    DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("families");
    ref.removeValue(); // Delete the data currently in the database so we can rewrite it.
    ref.setValue(object, new DatabaseReference.CompletionListener() {
        @Override
        public void onComplete(DatabaseError databaseError, DatabaseReference reference) {
            if (databaseError != null) {
                Log.e(TAG, "Failed to write message", databaseError.toException());
            }
        }
    });
}

Then you can debug your code based on the Exception generated

Upvotes: 2

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