BufferedReader txt = new BufferedReader( new FileReader( file ) );
    String line;
    maze = new Cell[size][size];
    int x;
    int y;
    String left = "left";
    String right = "right";
    String top = "top";
    String bottom = "bottom";

         while( ( line = txt.readLine() ) != null ){

         StringTokenizer t = new StringTokenizer(line, " ");
            x = Integer.parseInt(t.nextToken());
            y = Integer.parseInt(t.nextToken());

           if ( t.hasMoreTokens()){
            String operation = t.nextToken();

                switch( operation ){

                    case "PD":

                        maze[x][y] = new Cell();
                        maze[x][y].makeWall(top);
                        maze[x][y].makeWall(left);

                            if ( x != 0 && y != 0){
                                maze[x][y-1].makeWall(bottom);
                                maze[x-1][y].makeWall(right);
                            }
                            if ( x == 0 && y != 0 ){
                                maze[x][y-1].makeWall(bottom);
                            }
                            if ( x != 0 && y == 0 ){
                                maze[x-1][y].makeWall(right);
                            }
                        break;

                    case "P":

                        maze[x][y] = new Cell();
                        maze[x][y].makeWall(top);

                            if ( x != 0 && y != 0){
                                maze[x][y-1].makeWall(bottom);
                            }
                           if ( x == 0 && y != 0 ){
                                maze[x][y-1].makeWall(bottom);
                            }
                        break;

                    case "D":

                        maze[x][y] = new Cell();
                        maze[x][y].makeWall(left);

                        if ( x != 0 && y != 0){
                                maze[x-1][y].makeWall(right);
                            }
                            if ( x != 0 && y == 0 ){
                                maze[x-1][y].makeWall(right);
                            }
                        break;
                }
           }
           else {
               maze[x][y] = new Cell();
           }
        }