Designing Data Structure / Java data structures

Traditional data structures follow a structured programming paradigm. Object oriented programming has roots in structured programming, but adds in the concept of behavior locality. In short, the data is not just centralized, but the behavior (methods) that go with the data is centralized.

This allows data hiding (useful for maintenance, as the right data format tends to change over time), and opens the door to other more advance behaviors (polymorphisim is possible because the behavior is localized). However, it doesn't do much for a pure play data structure approach. The closest we have to old school data structures are objects which represent them.

When selecting a data structure, if you really don't have an idea of what is important, you really don't have the criteria which would allow you to select one data structure over another. Sure, you could just always use HashMap and HashSet and that would be fine a lot of the time; but, there are trivial examples where those selections are probably the worst choices. In short, you need to know the access patterns to make the right choice.

As duffymo suggests, you should consider an oop approach. Consider using something like the following example:

import java.util.ArrayList;

public class Product {

    private String name;
    private double price;
    private String company;
    private int total;
    private boolean available;

    public Product(String name, double price, String company, int total,
            boolean available) {
        super();
        this.name = name;
        this.price = price;
        this.company = company;
        this.total = total;
        this.available = available;
    }

    public String getName() {
        return name;
    }

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

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public String getCompany() {
        return company;
    }

    public void setCompany(String company) {
        this.company = company;
    }

    public int getTotal() {
        return total;
    }

    public void setTotal(int total) {
        this.total = total;
    }

    public boolean isAvailable() {
        return available;
    }

    public void setAvailable(boolean available) {
        this.available = available;
    }

    @Override
    public String toString() {
        return "Product [name=" + name + ", price=" + price + ", company="
                + company + ", total=" + total + ", available=" + available
                + "]";
    }

    public static void main(String[] args) {
        ArrayList<Product> products = new ArrayList<Product>();

        Product product1 = new Product("PlayStation 4", 300, "Sony", 10, true);
        Product product2 = new Product("XBOX One", 400, "Microsoft", 0, false);
        Product product3 = new Product("WiiU", 250, "Nintendo", 5, true);

        products.add(product1);
        products.add(product2);
        products.add(product3);

        System.out.println("-- Products --");
        for (Product product : products) {
            System.out.println(product.toString());
        }
    }
}

It will produce the following output:

-- Products --
Product [name=PlayStation 4, price=300.0, company=Sony, total=10, available=true]
Product [name=XBOX One, price=400.0, company=Microsoft, total=0, available=false]
Product [name=WiiU, price=250.0, company=Nintendo, total=5, available=true]

As you can see, you will be able to easily manage your list of items.

Hope it helps.

Clemencio Morales Lucas.