LanguagesString.java

public class LanguagesString {
    private String en;
    private String de;

    public String getEn() {
        return en;
    }

    public LanguagesString setEn(String en) {
        this.en = en;
        return this;
    }

    public String getDe() {
        return de;
    }

    public LanguagesString setDe(String de) {
        this.de = de;
        return this;
    }
}

Product.java

public class Product {
    private LanguagesString name;
    private LanguagesString description;
    private int number;
    private double price;

    public Product(LanguagesString name, LanguagesString description, int number, double price) {
        this.name = name;
        this.description = description;
        this.number = number;
        this.price = price;
    }

    // Return the languageString
    public LanguagesString getName() {
        return name;
    }
    // Return the language specific string
    public String getName(String language) {
        if (language.equals("en")) {
            return name.getEn();
        } else if (language.equals("de")) {
            return name.getDe();
        }
        return "";
    }

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

    // Return the languageString
    public LanguagesString getDescription() {
        return description;
    }
    // Return the language specific string
    public String getDescription(String language) {
        if (language.equals("en")) {
            return description.getEn();
        } else if (language.equals("de")) {
            return description.getDe();
        }
        return "";
    }

    public void setDescription(LanguagesString description) {
        this.description = description;
    }

    public double getPrice() {
        return price;
    }

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

    public int getNumber() {
        return number;
    }

    public void setNumber(int number) {
        this.number = number;
    }

    public String toString(String language) {
        return "Product-Nr.:" + getNumber() + "\n" +
                "Name: " + getName(language) +
                "\nDescription: " + getDescription(language) +
                "\nPrice: " + getPrice() + "\n";
    }
}

Shop.java

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;

public class Shop {
    public static void main(String[] args) {
        // Create the products list
        ArrayList<Product> productList = new ArrayList<>();

        // Create and add product 1
        LanguagesString n1 = new LanguagesString()
                .setEn("RAM")
                .setDe("RAM");
        LanguagesString d1 = new LanguagesString()
                .setEn("Storage for your PC")
                .setDe("Speicher für dein PC");
        Product p1 = new Product(n1, d1, 1, 199.99);
        productList.add(p1);

        // Create and add product 2
        LanguagesString n2 = new LanguagesString()
                .setEn("CPU")
                .setDe("Prozessor");
        LanguagesString d2 = new LanguagesString()
                .setEn("The brain of your computer")
                .setDe("Das Gehirn deines Computers");
        Product p2 = new Product(n2, d2, 2, 199.99);
        productList.add(p2);

        // What language does the user want?

        // Print all the products
        // Go through all the products and print each one

        // Select product to buy
        // If no command has been set, or the command is "pay" than skip

            // End the loop if user entered "pay"

            // Get product id and add to cart
                // Check whether it can be translated into an integer

            // Check whether the product exists and add it to the shopping cart

        // Check whether cart is empty or not

    }
}