工厂方法 读书笔记

工厂发法定义了一个创建对象的接口或者抽象类，但是有子类来决定要实例化的类是哪一个，工厂方法让类把实例化 推迟到子类。

package pattern;
import java.util.ArrayList;
public abstract class PizzaStore {
 SimplePizzaFactory factory;
 public PizzaStore() {
 }
 public PizzaStore(SimplePizzaFactory factory) {
  this.factory = factory;
 }
 public Pizza orderPizza(String type) {
  Pizza pizza;
  pizza = createPizza(type);
  pizza.prepare();
  pizza.bake();
  pizza.cut();
  pizza.box();
  return pizza;
 }
 abstract Pizza createPizza(String type);
}
class NYPizzaStore extends PizzaStore {
 Pizza createPizza(String item) {
  if (item.equals("cheese")) {
   return new NYStyleCheesePizza();
  } else if (item.equals("pepperoni")) {
   return new NYStylePepperoniPizza();
  } else if (item.equals("clam")) {
   return new NYStyleClamPizza();
  } else if (item.equals("veggie")) {
   return new NYStyleVeggiePizza();
  } else
   return null;
 }
}
class ChicagoPizzaStore extends PizzaStore {
 Pizza createPizza(String item) {
  if (item.equals("cheese")) {
   return new ChicagoStyleCheesePizza();
  } else if (item.equals("pepperoni")) {
   return new ChicagoStylePepperoniPizza();
  } else if (item.equals("clam")) {
   return new ChicagoStyleClamPizz();
  } else if (item.equals("veggie")) {
   return new ChicagoStyleVeggiePizza();
  } else
   return null;
 }
}
class CaliforniaPizzaStore extends PizzaStore {
 Pizza createPizza(String item) {
  if (item.equals("cheese")) {
   return new CaliforniaStyleCheesePizza();
  } else if (item.equals("pepperoni")) {
   return new CaliforniaStylePepperoniPizza();
  } else if (item.equals("clam")) {
   return new CaliforniaStyleClamPizza();
  } else if (item.equals("veggie")) {
   return new CaliforniaStyleVeggiePizza();
  } else
   return null;
 }
}
abstract class Pizza {
 String name;
 String dough;
 String sauce;
 ArrayList toppings = new ArrayList();
 public void prepare() {
  System.out.println("Preparing" + name);
  System.out.println("Tossing dough...");
  System.out.println("Adding sauce...");
  System.out.println("Adding toppings: ");
  for (int i = 0; i < toppings.size(); i++) {
   System.out.println("   " + toppings.get(i));
  }
 }
 public void bake() {
  System.out.println("Bake for 25 minutes at 350");
 }
 public void cut() {
  System.out.println("Cutting the pizza into diagonal slices");
 }
 public void box() {
  System.out.println("Place pizza in official PizzaStore box");
 }
 public String getName() {
  return name;
 }
}
class CheesePizza extends Pizza {
 public CheesePizza() {
  System.out.println("Cheesepizza");
 }
}
class NYStyleCheesePizza extends Pizza {
 public NYStyleCheesePizza() {
  name = "NY Style sauce and Cheese Pizza";
  dough = "Thin Crust Dough";
  sauce = "Marinara Sauce";
  toppings.add("Grated Reggiano Cheese");
 }
}
class ChicagoStyleCheesePizza extends Pizza {
 public ChicagoStyleCheesePizza() {
  name = "Chicago StyleDeep Dish Cheese Pizza";
  dough = "Extra Thick Crust Dough";
  sauce = "Plum Tomato Sauce";
  toppings.add("Shredded Mozzarella Cheese");
 }
 public void cut() {
  System.out.println("Cutting the pizza into square slices");
 }
}
class CaliforniaStyleCheesePizza extends Pizza {
 public CaliforniaStyleCheesePizza() {
  name = "California Style sauce and Cheese Pizza";
  dough = "Thin Crust Dough";
  sauce = "Marinara Sauce";
  toppings.add("Grated California Cheese");
 }
}
class PepperoniPizza extends Pizza {
 public PepperoniPizza() {
  System.out.println("PepperoniPizza");
 }
}
class NYStylePepperoniPizza extends Pizza {
 public NYStylePepperoniPizza() {
  name = "NY Style sauce and Cheese Pizza";
  dough = "Thin Crust Dough";
  sauce = "Marinara Sauce";
  toppings.add("Grated Pepperoni Cheese");
 }
}
class ChicagoStylePepperoniPizza extends Pizza {
 public ChicagoStylePepperoniPizza() {
  name = "Chicago StyleDeep Dish Cheese Pizza";
  dough = "Extra Thick Crust Dough";
  sauce = "Plum Tomato Sauce";
  toppings.add("Shredded Pepperoni Cheese");
 }
 public void cut() {
  System.out.println("Cutting the pizza into square slices");
 }
}
class CaliforniaStylePepperoniPizza extends Pizza {
 public CaliforniaStylePepperoniPizza() {
  name = "California Style sauce and Cheese Pizza";
  dough = "Thin Crust Dough";
  sauce = "Marinara Sauce";
  toppings.add("Grated Pepperoni Cheese");
 }
}
class ClamPizza extends Pizza {
 public ClamPizza() {
  System.out.println("ClamPizza");
 }
}
class NYStyleClamPizza extends Pizza {
 public NYStyleClamPizza() {
  name = "NY Style sauce and Cheese Pizza";
  dough = "Thin Crust Dough";
  sauce = "Marinara Sauce";
  toppings.add("Grated ClamPizza Cheese");
 }
}
class ChicagoStyleClamPizz extends Pizza {
 public ChicagoStyleClamPizz() {
  name = "Chicago StyleDeep Dish Cheese Pizza";
  dough = "Extra Thick Crust Dough";
  sauce = "Plum Tomato Sauce";
  toppings.add("Shredded Clam Cheese");
 }
 public void cut() {
  System.out.println("Cutting the pizza into square slices");
 }
}
class CaliforniaStyleClamPizza extends Pizza {
 public CaliforniaStyleClamPizza() {
  name = "California Style sauce and Cheese Pizza";
  dough = "Thin Crust Dough";
  sauce = "Marinara Sauce";
  toppings.add("Grated Clam Cheese");
 }
}
class VeggiePizza extends Pizza {
 public VeggiePizza() {
  System.out.println("VeggiePizza");
 }
}
class NYStyleVeggiePizza extends Pizza {
 public NYStyleVeggiePizza() {
  name = "NY Style sauce and Cheese Pizza";
  dough = "Thin Crust Dough";
  sauce = "Marinara Sauce";
  toppings.add("Grated VeggiePizza Cheese");
 }
}
class ChicagoStyleVeggiePizza extends Pizza {
 public ChicagoStyleVeggiePizza() {
  name = "Chicago StyleDeep Dish Cheese Pizza";
  dough = "Extra Thick Crust Dough";
  sauce = "Plum Tomato Sauce";
  toppings.add("Shredded Veggie Cheese");
 }
 public void cut() {
  System.out.println("Cutting the pizza into square slices");
 }
}
class CaliforniaStyleVeggiePizza extends Pizza {
 public CaliforniaStyleVeggiePizza() {
  name = "California Style sauce and Cheese Pizza";
  dough = "Thin Crust Dough";
  sauce = "Marinara Sauce";
  toppings.add("Grated Veggie Cheese");
 }
}
 
 
public class PizzaTestDrive {
 public static void main(String[] args) {
  PizzaStore nyStore = new NYPizzaStore();
  PizzaStore chicagoStore = new ChicagoPizzaStore();
  Pizza pizza = nyStore.orderPizza("cheese");
  System.out.println("Ethan ordered a " + pizza.getName() + "\n");
  pizza = chicagoStore.orderPizza("cheese");
  System.out.println("Joel ordered a " + pizza.getName() + "\n");
 }
}
 
 
public class SimplePizzaFactory {
 public Pizza createPizza(String type) {
  Pizza pizza = null;
  if (type.equals("cheese")) {
   pizza = new CheesePizza();
  }else if(type.equals("pepperoni")){
   pizza=new PepperoniPizza();
  }else if(type.equals("clam")){
   pizza=new ClamPizza();
  }else if(type.equals("veggie")){
   pizza=new VeggiePizza();
  }  
  return pizza;
 }
}