我们仍然以上一篇文章的案例为主,画出抽象工厂模式下的类图。
首先仍然是Pizza种类相关的几个类。
package com.szh.factory.abstractfactory.pizza; /** * 声明Pizza类为抽象类 */ public abstract class Pizza { //Pizza名称 protected String name; //准备原材料,不同的披萨不一样。因此,我们做成抽象方法,具体的原材料实现交给它的子类去完成 public abstract void prepare(); //烘烤 public void bake() { System.out.println(name + " baking;"); } //切割 public void cut() { System.out.println(name + " cutting;"); } //打包 public void box() { System.out.println(name + " boxing;"); } public void setName(String name) { this.name = name; } }
package com.szh.factory.abstractfactory.pizza; public class LDPepperPizza extends Pizza { @Override public void prepare() { setName("伦敦的胡椒pizza"); System.out.println("伦敦的胡椒pizza 准备原材料"); } }
package com.szh.factory.abstractfactory.pizza; public class LDCheesePizza extends Pizza { @Override public void prepare() { setName("伦敦的奶酪pizza"); System.out.println("伦敦的奶酪pizza 准备原材料"); } }
package com.szh.factory.abstractfactory.pizza; public class BJPepperPizza extends Pizza { @Override public void prepare() { setName("北京的胡椒pizza"); System.out.println("北京的胡椒pizza 准备原材料"); } }
package com.szh.factory.abstractfactory.pizza; public class BJCheesePizza extends Pizza { @Override public void prepare() { setName("北京的奶酪pizza"); System.out.println("北京的奶酪pizza 准备原材料"); } }
下面是抽象工厂和工厂方法的区别之处。
package com.szh.factory.abstractfactory.order; import com.szh.factory.abstractfactory.pizza.Pizza; //一个抽象工厂模式的抽象层(接口) public interface AbsFactory { //让下面的工厂子类来具体实现 public Pizza createPizza(String orderType); }
package com.szh.abstractfactory.order; import com.szh.abstractfactory.pizza.BJCheesePizza; import com.szh.abstractfactory.pizza.BJPepperPizza; import com.szh.abstractfactory.pizza.Pizza; public class BJFactory implements AbsFactory { @Override public Pizza createPizza(String orderType) { Pizza pizza = null; if("cheese".equals(orderType)) { pizza = new BJCheesePizza(); } else if ("pepper".equals(orderType)){ pizza = new BJPepperPizza(); } return pizza; } }
package com.szh.abstractfactory.order; import com.szh.abstractfactory.pizza.LDCheesePizza; import com.szh.abstractfactory.pizza.LDPepperPizza; import com.szh.abstractfactory.pizza.Pizza; public class LDFactory implements AbsFactory { @Override public Pizza createPizza(String orderType) { Pizza pizza = null; if ("cheese".equals(orderType)) { pizza = new LDCheesePizza(); } else if ("pepper".equals(orderType)) { pizza = new LDPepperPizza(); } return pizza; } }
package com.szh.factory.abstractfactory.order; import com.szh.factory.abstractfactory.pizza.Pizza; import java.util.Scanner; public class OrderPizza { AbsFactory absFactory; public OrderPizza(AbsFactory absFactory) { setFactory(absFactory); } private void setFactory(AbsFactory absFactory) { Pizza pizza = null; String orderType = ""; // 用户输入 this.absFactory = absFactory; do { orderType = getType(); // factory 可能是北京的工厂子类,也可能是伦敦的工厂子类 pizza = absFactory.createPizza(orderType); if (pizza != null) { // 订购ok pizza.prepare(); pizza.bake(); pizza.cut(); pizza.box(); } else { System.out.println("订购失败"); break; } } while (true); } // 写一个方法,可以获取客户希望订购的披萨种类 private String getType() { Scanner scanner = new Scanner(System.in); System.out.println("请输入 pizza 种类: "); String str = scanner.nextLine(); return str; } }
最后是测试类。
package com.szh.abstractfactory; import com.szh.abstractfactory.order.BJFactory; import com.szh.abstractfactory.order.LDFactory; import com.szh.abstractfactory.order.OrderPizza; import java.util.Scanner; public class MainTest { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String content = scanner.next(); if ("Beijing".equals(content)) { new OrderPizza(new BJFactory()); } else if ("London".equals(content)) { new OrderPizza(new LDFactory()); } else { System.out.println("无法预先匹配Pizza种类...."); scanner.close(); } } }