Java设计模式（五） 工厂模式

1，定义抽象产品类

package com.pattern.factory;
 
import java.util.ArrayList;
 
public abstract class Pizza {
	String name;
	String dough;
	String sauce;
	ArrayList toppings = new ArrayList();
 
	void prepare(){
		System.out.println("Prepareing "+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));
		}
	}
 
	void bake(){
		System.out.println("Bake for 25 minutes at 350");
	}
 
	void cut(){
		System.out.println("Cutting the pizza into diagonal slices");
	}
 
	void box(){
		System.out.println("Place pizza in official PizzaStore box");
	}
 
	public String getName(){
		return name;
	}
}

2，具体产品类

package com.pattern.factory;
public class ChicagoStyleCheesePizza extends Pizza {
  public ChicagoStyleCheesePizza(){
  name = "Chicago Style Deep Dish Cheese Pizza";
  dough = "Extra Thick Crust Dough";
  sauce = "Plum Tomato Sauce";
  
  toppings.add("Shredded Mozzarella Cheese");
 }
 
 void cut(){
  System.out.println("Cutting the pizza into square slices");
 }
}

package com.pattern.factory;
 
public 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");
	}
}

3，定义抽象工厂类

package com.pattern.factory;
 
public abstract class PizzaStore {
 
	public Pizza orderPizza(String type){
		Pizza pizza ;
		pizza = createPizza(type);
		pizza.prepare();
		pizza.bake();
		pizza.cut();
		pizza.box();
 
		return pizza;
	}
 
	protected abstract Pizza createPizza(String type) ;
 
}

4，定义具体工厂类

package com.pattern.factory;
 
import com.pattern.factory.bean.ChicagoStyleClamPizza;
import com.pattern.factory.bean.ChicagoStylePepperoniPizza;
import com.pattern.factory.bean.ChicagoStyleVeggiePizza;
 
public class ChicagoPizzaStore extends PizzaStore {
 
	/**
	 * @see com.pattern.factory.PizzaStore#createPizza(java.lang.String)
	 */
	@Override
	protected Pizza createPizza(String type) {
		if(type.equals("cheese")){
			return new ChicagoStyleCheesePizza();
		} else if(type.equals("veggie")){
			return new ChicagoStyleVeggiePizza();
		} else if(type.equals("clam")){
			return new ChicagoStyleClamPizza();
		} else if(type.equals("pepperoni")){
			return new ChicagoStylePepperoniPizza();
		} else {
			return null;
		}
	}
 
}

package com.pattern.factory;
 
import com.pattern.factory.bean.NYStyleClamPizza;
import com.pattern.factory.bean.NYStylePepperoniPizza;
import com.pattern.factory.bean.NYStyleVeggiePizza;
 
public class NYPizzaStore extends PizzaStore {
 
	/**
	 * @see com.pattern.factory.PizzaStore#createPizza(java.lang.String)
	 */
	@Override
	protected Pizza createPizza(String type) {
		if(type.equals("cheese")){
			return new NYStyleCheesePizza();
		} else if(type.equals("veggie")){
			return new NYStyleVeggiePizza();
		} else if(type.equals("clam")){
			return new NYStyleClamPizza();
		} else if(type.equals("pepperoni")){
			return new NYStylePepperoniPizza();
		} else {
			return null;
		}
	}
 
}

5，测试类

package com.pattern.factory;
 
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 order a "+ pizza.getName()+"\n");
	}
}

测试结果：

Prepareing NY Style Sauce and Cheese Pizza

Tossing dough...

Adding sauce...

Adding toppings:

 Grated Reggiano Cheese

Bake for 25 minutes at 350

Cutting the pizza into diagonal slices

Place pizza in official PizzaStore box

Ethan ordered a NY Style Sauce and Cheese Pizza

Prepareing Chicago Style Deep Dish Cheese Pizza

Tossing dough...

Adding sauce...

Adding toppings:

 Shredded Mozzarella Cheese

Bake for 25 minutes at 350

Cutting the pizza into square slices

Place pizza in official PizzaStore box

Joel order a Chicago Style Deep Dish Cheese Pizza

类图如下所示：