DataTable Group

@Named("dtGroupView")
@ViewScoped
public class GroupView implements Serializable {

    private static final String[] MANUFACTORS;
    private static final String[] PLAYER_NAMES;

    private List<Sale> sales;
    private Integer lastYearTotal;
    private Integer thisYearTotal;
    private List<Integer> years;
    private List<Player> players;

    static {
        MANUFACTORS = new String[10];
        MANUFACTORS[0] = "Bamboo Watch";
        MANUFACTORS[1] = "Black Watch";
        MANUFACTORS[2] = "Blue Band";
        MANUFACTORS[3] = "Blue T-Shirt";
        MANUFACTORS[4] = "Brown Purse";
        MANUFACTORS[5] = "Chakra Bracelet";
        MANUFACTORS[6] = "Galaxy Earrings";
        MANUFACTORS[7] = "Game Controller";
        MANUFACTORS[8] = "Gaming Set";
        MANUFACTORS[9] = "Gold Phone Case";

        PLAYER_NAMES = new String[10];
        PLAYER_NAMES[0] = "Lionel Messi";
        PLAYER_NAMES[1] = "Cristiano Ronaldo";
        PLAYER_NAMES[2] = "Arjen Robben";
        PLAYER_NAMES[3] = "Franck Ribery";
        PLAYER_NAMES[4] = "Ronaldinho";
        PLAYER_NAMES[5] = "Luis Suarez";
        PLAYER_NAMES[6] = "Sergio Aguero";
        PLAYER_NAMES[7] = "Zlatan Ibrahimovic";
        PLAYER_NAMES[8] = "Neymar Jr";
        PLAYER_NAMES[9] = "Andres Iniesta";
    }

    @PostConstruct
    public void init() {
        sales = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            sales.add(new Sale(MANUFACTORS[i], getRandomAmount(), getRandomAmount(), getRandomPercentage(), getRandomPercentage()));
        }

        years = new ArrayList<>();
        years.add(2010);
        years.add(2011);
        years.add(2012);
        years.add(2013);
        years.add(2014);

        players = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            players.add(new Player(PLAYER_NAMES[i], generateRandomGoalStatsData()));
        }
    }

    public List<Sale> getSales() {
        return sales;
    }

    private int getRandomAmount() {
        return (int) (Math.random() * 100000);
    }

    private int getRandomPercentage() {
        return (int) (Math.random() * 100);
    }

    public Integer getLastYearTotal() {
        if (lastYearTotal == null) {
            lastYearTotal = sales.stream().mapToInt(Sale::getLastYearSale).sum();
        }
        return lastYearTotal;
    }

    public Integer getThisYearTotal() {
        if (thisYearTotal == null) {
            thisYearTotal = sales.stream().mapToInt(Sale::getThisYearSale).sum();
        }
        return thisYearTotal;
    }

    public List<Integer> getYears() {
        return years;
    }

    public int getYearCount() {
        return years.size();
    }

    public List<Player> getPlayers() {
        return players;
    }

    private Map<Integer, Integer> generateRandomGoalStatsData() {
        Map<Integer, Integer> stats = new LinkedHashMap<>();
        for (int i = 0; i < 5; i++) {
            stats.put(years.get(i), getRandomGoals());
        }

        return stats;
    }

    private int getRandomGoals() {
        return (int) (Math.random() * 50);
    }
}

public class Sale implements Serializable {

    private String manufacturer;
    private int lastYearSale;
    private int thisYearSale;
    private int lastYearProfit;
    private int thisYearProfit;

    public Sale() {
    }

    public Sale(String manufacturer, int lastYearSale, int thisYearSale, int lastYearProfit, int thisYearProfit) {
        this.manufacturer = manufacturer;
        this.lastYearSale = lastYearSale;
        this.thisYearSale = thisYearSale;
        this.lastYearProfit = lastYearProfit;
        this.thisYearProfit = thisYearProfit;
    }

    public int getLastYearProfit() {
        return lastYearProfit;
    }

    public void setLastYearProfit(int lastYearProfit) {
        this.lastYearProfit = lastYearProfit;
    }

    public int getLastYearSale() {
        return lastYearSale;
    }

    public void setLastYearSale(int lastYearSale) {
        this.lastYearSale = lastYearSale;
    }

    public String getManufacturer() {
        return manufacturer;
    }

    public void setManufacturer(String manufacturer) {
        this.manufacturer = manufacturer;
    }

    public int getThisYearProfit() {
        return thisYearProfit;
    }

    public void setThisYearProfit(int thisYearProfit) {
        this.thisYearProfit = thisYearProfit;
    }

    public int getThisYearSale() {
        return thisYearSale;
    }

    public void setThisYearSale(int thisYearSale) {
        this.thisYearSale = thisYearSale;
    }
}

public class Player {

    private String name;

    private Map<Integer, Integer> goals;

    public Player() {
        goals = new LinkedHashMap<>();
    }

    public Player(String name, Map<Integer, Integer> goals) {
        this.name = name;
        this.goals = goals;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getGoals(int year) {
        return goals.get(year);
    }
}