Cannot convert HashMap data to List of objects (Model class)

Question

I have list of addresses in the Firebase Database. It is retrieved like this:

    addressesRef
        .addListenerForSingleValueEvent(object : ValueEventListener {
            override fun onDataChange(snapshot: DataSnapshot) {
                if (snapshot.exists()) {

                    
                    //Toast.makeText(this@AddressActivity, "Addresses fetched!", Toast.LENGTH_SHORT).show()
                }
            }

Notice the the addresses with 2 IDs (they got fetched in reverse order)

I am trying to convert this into an ArrayList<Address> where Address is my model class. How do I do that?

Do you need the value of a single child (Ad_100000) or of all children (Ad_100000, Ad_100001 etc)? — Alex Mamo
– Alex Mamo, Commented Aug 10, 2021 at 14:21

Frank van Puffelen · Accepted Answer · 2021-08-10 14:05:21Z

1

It looks like what you have in the database is a Map<String, Address> and not a List<Address>. If you want to get just the Address value, you can either load the map and just get its value, or (preferred):

override fun onDataChange(snapshot: DataSnapshot) {
    if (snapshot.exists()) {
        for (addressSnapshot in snapshot.children) {
            val address = addressSnapshot.getValue<Address>();
            ...
        }
    }
}

answered Aug 10, 2021 at 14:05

Frank van Puffelen

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1 Comment

who-aditya-nawandar Over a year ago

Where were you Sir?! I had to waste so many hours for this. Thank you!

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