Vfrdtyky

I have been building a multiplayer checker game for my class project.
The below code is in Room class because every game should have a checkerboard.

I converted to 2D List because Firebase does not serialize arrays.

Each of object stored in the list is a subclass of Checker, including nullc (a substitute for null). The reason why I store nullc in the list is that the list has two rows consist of only nulls, and Firebase does not store the index of those two rows.

this.checkerList = new ArrayList<List<Checker>>();

Checker nullc = new NullChecker();

Checker  checkerArray = new Checker

    {{nullc, new RedChecker(0,1), nullc, new RedChecker(0,3),

      nullc, new RedChecker(0,5), nullc, new RedChecker(0,7)},

      {new RedChecker(1,0), nullc, new RedChecker(1,2),nullc, new RedChecker(1,4), nullc, new RedChecker(1,6), nullc},

      {nullc, new RedChecker(2,1), nullc, new RedChecker(2,3), nullc, new RedChecker(2,5), nullc, new RedChecker(2,7)},

      {nullc, nullc, nullc, nullc,nullc, nullc,nullc, nullc},

      {nullc, nullc, nullc, nullc,nullc, nullc,nullc, nullc},

      {new BlackChecker(5,0), nullc, new BlackChecker(5,2),nullc, new BlackChecker(5,4), nullc, new BlackChecker(5,6), nullc},

      {nullc, new BlackChecker(6,1), nullc, new BlackChecker(6,3), nullc, new BlackChecker(6,5), nullc, new BlackChecker(6,7)},

      {new BlackChecker(7,0), nullc, new BlackChecker(7,2),nullc, new BlackChecker(7,4), nullc, new BlackChecker(7,6), nullc}};



for(int r = 0; r < checkerArray.length; r++){

    List <Checker> row = new ArrayList <Checker>();

    for(int c = 0; c < checkerArray[r].length; c++){

        row.add(checkerArray[r][c]);

    }

    this.checkerList.add(row);

}

The problem I have now is the list stores fine in Firebase database. However, when I retrieve the whole list from the database, the subclasses are not subclasses anymore.

    refThisRoom.addValueEventListener(new ValueEventListener() {

        @Override

        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

            if(dataSnapshot.getValue(Room.class).getPlayer2() != null){

                turn = dataSnapshot.getValue(Room.class).getTurn();

                checkerList = dataSnapshot.getValue(Room.class).getCheckerList();



                for(int r = 0; r < checkerList.size(); r++){

                    Log.d("checkerList", "row" + String.valueOf(r));

                    Log.d("checkerList", "rowSize" + String.valueOf(checkerList.size()));

                    for(int c = 0; c < checkerList.get(r).size(); c++){

                        Log.d("checkerList", "Column" + String.valueOf(c));

                        Log.d("checkerList", "ColumnSize" + String.valueOf(checkerList.get(r).size()));

                        Log.d("checkerList","hello: "+checkerList.get(r).get(c).getClass().getSimpleName());

                    }



                }

                Toast.makeText(BlackCheckerActivity.this,"Player Entered",Toast.LENGTH_LONG).show();

                updateAllButtons();

                disableButtons();

            }

            else{

                Toast.makeText(BlackCheckerActivity.this,"Waiting for another player",Toast.LENGTH_LONG).show();

            }

        }



        @Override

        public void onCancelled(@NonNull DatabaseError databaseError) {



        }

    });

Instead of returning BlackChecker, RedChecker, and NullChecker, it is just returning checker. I am stuck now because I am using instanceof to determine each checker's move.

I solved the issue by adding another field called "type" of type string to the parent class in the constructor. For the subclasses, when I create a subclass, I wrote

     new RedChecker(row, column, "RedChecker")

     new BlackChecker(row, column, "BlackerChecker")

     new NullChecker(row, column, "NullChecker").

When retrieving the list of Checker class back, I replaced all the superclass in the object with newly initiated subclasses. Something like

    if(checkerList.get(r).get(c).getType().equals("Red/Black/NullChecker")){

      checkerList.get(r).set(c, new Red/Black/NullChecker(checkerList.get(r).get(c).getRow(), checkerList.get(r).get(c).getColumn(), checkerList.get(r).get(c).getType())

    }