I’m trying to apply object orientation to a Java program

Question

I’m trying to apply object orientation to this program and I wanted to start with the exchange of these ifs, does anyone have any hint of what to put in place?

import java.util.*;

public class MenuPizza {

    protected static Scanner l;
    private boolean execute;
    protected List<Pizzas> pizzas;

    public static void main(String[] args) {
        new MenuPizza();
    }

    public MenuPizza() {

        l = new Scanner(System.in);
        execute = true;
        pizzas = new ArrayList<Pizzas>();

        System.out.println("Olá\n" + "Seja bem-vindo ao nosso menu de pizzas");

        while (execute) {
            String opcao = menu();
            if (opcao.equalsIgnoreCase("1")) {
                inserirPizza();
            } else if (opcao.equals("2")) {
                listarPizza();
            } else if (opcao.equals("3")) {
                removerPizza();
            } else if (opcao.equals("4")) {
                alterarPizza();
            } else if (opcao.equals("5")) {
                exibirMenu();
            } else if (opcao.equals("6")) {
                execute = false;
            } else {
                System.out.println("\nOpção Inválida\n");
            }
        }
    }

    private static String menu() {
        System.out.println("");
        System.out.println("1. Inserir Pizzas");
        System.out.println("2. Listar Pizzas");
        System.out.println("3. Remover Pizzas");
        System.out.println("4. Alterar Preço da Pizza");
        System.out.println("5. Exibir Menu de Opções");
        System.out.println("6. Sair");
        System.out.println("\r\nDigite uma das opções :");
        return l.nextLine();

    }

    public class Pizzas {

        public String sabor;
        public String preço;

        public Pizzas() {
        }

        public String getSabor() {
            return sabor;
        }

        public void setSabor(String sabor) {
            this.sabor = sabor;
        }

        public String getPreço() {
            return preço;
        }

        public void setPreço(String preço) {
            this.preço = preço;
        }
    }

    private void inserirPizza() {
        boolean inserindo = true;
        while (inserindo) {
            System.out.println("\r\nInserir Pizzas");

            Pizzas d = new Pizzas();
            d.setSabor(textInput("\r\nDigite o sabor da pizza: "));
            d.setPreço(textInput("\nDigite o preço da pizza: "));

            String inserir = textInput("\nAdicionar pizza ?  (S/N)");

            if (inserir.equalsIgnoreCase("s")) {
                System.out.println("\r\nPizza adicionada ao menu");
                pizzas.add(d);
            }

            else if (inserir.equalsIgnoreCase("n")) {
                System.out.println("\r\nPizza não adicionada");
            }

            else {
                System.out.println("\nOpção inválida\n");
            }
            inserindo = false;
        }
    }

    private void listarPizza() {
        if (pizzas.size() == 0) {
            System.out.println("\r\nAinda não há pizzas adicionadas\n");

        } else {
            System.out.println("\r\nListar Pizzas\n");

            for (Pizzas pizzas2 : pizzas) {
                System.out.println("Sabor: " + pizzas2.getSabor());
                System.out.println("Preço: " + pizzas2.getPreço() + "\n");
            }

        }

    }

    private void removerPizza() {
        listarPizza();

        String remover = textInput("Digite o sabor da pizza que deseja remover: ");

        for (Pizzas pizzas2 : pizzas) {
            if (pizzas2.sabor.equalsIgnoreCase(remover)) {
                remover += pizzas.remove(pizzas2);

                System.out.println("\nPizza removida\n");

                listarPizza();
            }

        }

    }

    private void alterarPizza() {
        listarPizza();

        String sabor = textInput("Digite o sabor da pizza que deseja alterar o preço: ");
        String novoPreço = textInput("\nDigite o novo preço: ");

        for (Pizzas pizzas2 : pizzas) {
            if (pizzas2.getSabor().equalsIgnoreCase(sabor)) {
                pizzas2.setPreço(novoPreço);

                System.out.println("\nPreço alterado\n");

                listarPizza();
            }
        }

    }

    private void exibirMenu() {
        menu();
    }

    private String textInput(String fim) {
        System.out.println(fim);
        return l.nextLine();
    }

}

Answer 1

People want to do object-oriented, but have no idea what that is. They actually learn fragments of what OOP is and try to apply it. Usually you get a monster and you get the worst of both worlds.

Object orientation is not panacea and only works if the programmer knows how to organize the code very well and understand deeply why OO is used, what advantages it will bring doing so, which has the ability to see when something is wrong, when OO there is not suitable.

Object-oriented programming is difficult and even experienced programmers often make mistakes. It is even more wrong when there is a lack of understanding of the imperative before trying OO. If it is to do OO wrong, it is better not to do it at all. If not to see a clear benefit is not worth the effort.

My informal estimate is that over 90 percent of programmers think and talk about object-oriented programming, but they don’t even realize they’re not actually doing it. It has a minority who do OO at various levels of quality. So I don’t understand why people insist on trying something they never understand how to do.

I already say that the imperative can be better than what is written there and that the attempt to leave object oriented left the code more confused than if it made more procedural.

The first problem with this code is that it does a lot of different things within a single class. It is the main, it is a menu, it is the CRUD, it is the data repository, it is the business rule, IE, none of this code is object oriented already in the base.

No use eliminating a few ifs that the code will not magically be object oriented. You can delete the if and will not be anything object oriented. You can create a map, but the gain in readability and maintainability is usually zero, it can even be negative.

It is possible to use a rather complex logic to create new options in the menu without tampering with the code, just adding novelty. It’s not worth doing this, it’s not worth it if the project had half a million lines of code and was run by a team of dozens of people and had news almost every day, which is where the object orientation shines.

But for whom? To call private things? It makes no sense.

I do not understand why it has protected members. There may be some reason, but it seems that it was placed so randomly.

I don’t understand this class Pizzas (the name should be singular because it represents only a pizza) makes within this class.

The encapsulation of this last class is bad. And I question if it is necessary. Clearly it was made as cake recipe.

I’m sorry, but the proper refactoring in this code is to start over. Or try to do something less ambitious.