Retrieve a hashmap from firebase to populate FirebaseRecycler, null HashMap

Question

I am trying to retrieve a HashMap from Firebase to populate my Firebase RecyclerView below is my model class that I am trying to retrieve:

public class Employee{
private HashMap<String, Person> PeopleMap; 
// =  new HashMap<String, Person>();

public Employee () {
}

public Employee(HashMap<String, Person> people) {
    this.PeopleMap= people;
}

public HashMap<String, Person> getMap() {
    return PeopleMap;
}
public void setMap(HashMap<String, Person> people) {
    this.PeopleMap= people;
}
}

Person class

public class Person {
private String ImageUrl;
private  String Name;
private String  Pay;
public Person() {
}

public Person(String name, String imageUrl, String pay, 
 ) {
    ImageUrl = imageUrl;
    Name = name;
    Pay = pay;

}

public String getImageUrl() {
    return ImageUrl;
}

public void setImageUrl(String imageUrl) {
    ImageUrl = imageUrl;
}

public String getName() {
    return Name;
}

public void setName(String name) {
    Name = name;
}

public String getPay() {
    return Pay;
}

public void setPrice(String pay) {
    Pay= pay;
}
}

Now the problem is that when i retrieve my Employe model class in firebase recycler it is not null but if i retrieve my Hashmap from there the size of map is zero while there are items on the map below is what i am doing

Firebase REycler

        @Override
        protected void onBindViewHolder( ConvoViewHolder holder,  int 
        position,  Employee model) {
            if (model.equals(null)){
                Toast.makeText(OrderConversation.this, "object is null", 
                Toast.LENGTH_SHORT).show();
            }
            else
            {
                HashMap<String, OrderItem> cartitems =  model.getCart();
                int i = cartitems.size();
             if (i==0)
                    {
                        Toast.makeText(OrderConversation.this, "null 
                        map", Toast.LENGTH_SHORT).show();
                    }
                    else {
                        Toast.makeText(OrderConversation.this, "size of 
                        map in bind"+ Integer.toString(i),
                        Toast.LENGTH_SHORT).show();
                    }
            }
        }
    };
    mEmpList.setAdapter(adapter);
    adapter.startListening();

My Database structure is like below with employee as a parent node and

Sorry I had to type it i hope it is clear to everyone about what kind of str i have. i want to retrieve from department node so that i can get two object (DHead1 & Dhead2 ), which have different no of elements in them as Dhead has 3 objects of person class and Dhead2 has 2. so one way i can go is either i load them first into a list and them use them or the other way that i am using now i.e. retrieve them as an object which contains the map of person class object.

i tried this below and i am getting values fine but inside onbindview its not working

mDatabase.addValueEventListener(new ValueEventListener() {
             @Override
             public void onDataChange(DataSnapshot dataSnapshot) {
                 for(DataSnapshot ds: dataSnapshot.getChildren()){
                     GenericTypeIndicator<Map<String, Person>> to = new 
                     GenericTypeIndicator<Map<String, Person>>() {};
                     Map<String, Person> map = ds.getValue(to);
                     for(Person ml:convoModels.values()) {
                         String name = ml.getName();
                         Toast.makeText(context, "name is "+ name, 
                         Toast.LENGTH_SHORT).show();
                     }
                   }
              }
             @Override
             public void onCancelled(DatabaseError databaseError) {
             }
         });

Answer 1

You are not getting anything because the fields in your model class are different than the fileds in your database. See, in your database you have imageUrl and in your model class you have ImageUrl. Keep in mind that when you are using a getter named getImageUrl(), Firebase will search for a field named imageUrl and not ImageUrl. The key for solving your problem is to change the name of your fields so it can start with a lower case like this:

private String imageUrl;
private  String name;
private String  pay;

Edit: See also the correct way of using the Employee class.

public class Employee {
    private HashMap<String, Person> peopleMap;

    public Employee() {}

    public Employee(HashMap<String, Person> peopleMap) {
        this.peopleMap = peopleMap;
    }

    public HashMap<String, Person> getPeopleMap() {
        return peopleMap;
    }
}