Diet
Write an application to manage a diet by means of nutritional values computation.
The application must allow the definition of raw materials and their
use as ingredients for recipes.
All the classes must be in the package "diet".
R1 - Raw Materials
The system works though the facade class Food.
To define a raw material, we can use the method defineRawMaterial() that accepts as arguments
the name, the kilo-calories, the amount of proteins, carbohydrates (carbs), and fat;
all the values refer to 100 grams of raw material.
To retrieve some information about the raw materials we can use the method rawMaterials() which
returns a list of raw materials, sorted by name in alphabetic order.
To get info about a specific material, we can use the method getRawMaterial() that accepts the name
of the raw material and returns the corresponding raw material.
The raw materials returned by the above methods are objects implementing the interface NutritionalElement,
which provides the getter methods getName(), getCalories(), getProteins(), getCarbs(), getFat().
Calories are expressed in KCal, while proteins, carbs, and fat are expressed in grams.
Moreover the interface includes the method per100g() that indicates whether the values
refer to 100 grams of nutritional element or represent an absolute value. For raw materials
the nutritional values are always expressed per 100 grams, therefore the method returns true.
R2 - Products
The diet may include also pre-packaged products (e.g. an ice cream or a snack).
Products are defined by means of the method defineProduct() of class Food
accepting as arguments the name, the kilo-calories, the amount of proteins, carbohydrates (carbs), and fat.
Such values express the value for the whole product, therefore the method per100g() returns false.
To retrieve information about the products we can use the method products() of class Food that returns
a collection of products sorted by name. To get information about a specific product, method getProduct() is
available that accepts the name of the product and returns the corresponding object, which implements
the interface nutritionalElement.
R3 - Recipes
Raw materials can be combined as ingredients of recipes.
Toe define a recipe we ought to create a new Recipe object that will be added
with the ingredients. The constructor of class Recipe accepts as arguments the
name of the recipe and the Food object that contains the ingredients.
A new ingredient can be added to a recipe by means of method addIngredient() that accepts
as arguments the name of the raw material and the amount in grams.
Class Recipe implements the interface NutritionalElement and the values are
expressed per 100 grams.
When the recipe is created, it is automatically added to the the content of the
corresponding Food object. An to retrieve the information about the recipes we
can use the method recipes(), of class Food, that returns a collection
of recipes sorted by name. To get information regarding a specific recipe we
can use the method getRecipe() that accepts as argument the name of the
recipe and return the corresponding recipe.
Warning:
While the sum of the amounts of ingredients (in grams) of a recipe is not
necessarily equal to 100g, the nutritional values of the recipe must refer
to an hypothetical portion of 100 grams.
R4 - Menu
A menu consists of portions of either recipes or pre-packaged products.
Menus are represented by class Menu whose constructor accepts as arguments
the name and the reference to the Food object containing the information about
products and recipes.
To add a portion of a recipe to the menu we can use the method addRecipe() that
accepts as argument the name of the recipe and the size of the portion, in grams.
To add an item of a pre-packaged product, we can use the method addProduct() that
accepts as argument the name of the product.
Class Menu implements the NutritionalElement interface; in this case the values are
referred to the whole menu and not to 100 grams.