Wzorzec budowniczego
Z Wikipedii
Wzorzec budowniczego (ang. Builder pattern) jest to wzorzec projektowy, który pozwala na rozdzielenie skomplikowanej struktury klasy od jej reprezentacji.
[edytuj] Przykład kodu
[edytuj] Java
/** "Product" */ class Pizza { String dough = ""; private String sauce = ""; private String topping = ""; public void setDough(String dough) { this.dough = dough; } public void setSauce(String sauce) { this.sauce = sauce; } public void setTopping(String topping) { this.topping = topping; } } /** "Abstract Builder" */ abstract class PizzaBuilder { protected Pizza pizza; public Pizza getPizza() { return pizza; } public void createNewPizzaProduct() { pizza = new Pizza(); } public abstract void buildDough(); public abstract void buildSauce(); public abstract void buildTopping(); } /** "ConcreteBuilder" */ class HawaiianPizzaBuilder extends PizzaBuilder { public void buildDough() { pizza.setDough("cross"); } public void buildSauce() { pizza.setSauce("mild"); } public void buildTopping() { pizza.setTopping("ham+pineapple"); } } /** "ConcreteBuilder" */ class SpicyPizzaBuilder extends PizzaBuilder { public void buildDough() { pizza.setDough("pan baked"); } public void buildSauce() { pizza.setSauce("hot"); } public void buildTopping() { pizza.setTopping("pepperoni+salami"); } } /** "Director" */ class Waiter { private PizzaBuilder pizzaBuilder; public void setPizzaBuilder(PizzaBuilder pb) { pizzaBuilder = pb; } public Pizza getPizza() { return pizzaBuilder.getPizza(); } public void constructPizza() { pizzaBuilder.createNewPizzaProduct(); pizzaBuilder.buildDough(); pizzaBuilder.buildSauce(); pizzaBuilder.buildTopping(); } } /** A customer ordering a pizza. */ class BuilderExample { public static void main(String[] args) { Waiter waiter = new Waiter(); PizzaBuilder hawaiian_pizzabuilder = new HawaiianPizzaBuilder(); PizzaBuilder spicy_pizzabuilder = new SpicyPizzaBuilder(); waiter.setPizzaBuilder( hawaiian_pizzabuilder ); waiter.constructPizza(); Pizza pizza = waiter.getPizza(); } }