文档介绍：封面 Java Java Java Java 设计模式课程设计参考 2013-6-9 1 第 1 组工厂方法模式 2013-6-9 2 工厂方法模式(别名:虚拟构造) 定义一个用于创建对象的接口,让子类决定实例化哪一个类。 Factory Factory Factory Factory Method Method Method Method 使一个类的实例化延迟到其子类。 Mediator Pattern Mediator Pattern Mediator Pattern Mediator Pattern (Another Name: Virtual Constructor) (Another Name: Virtual Constructor) (Another Name: Virtual Constructor) (Another Name: Virtual Constructor) Define an interface for creating an object, but let subclasses decide which Define an interface for creating an object, but let subclasses decide which Define an interface for creating an object, but let subclasses decide which Define an interface for creating an object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to class to instantiate. Factory Method lets a class defer instantiation to class to instantiate. Factory Method lets a class defer instantiation to class to instantiate. Factory Method lets a class defer instantiation to subclasses. subclasses. subclasses. subclasses. 一、概述 2013-6-9 3 当系统准备为用户提供某个类的子类的实例, 又不想让用户代码和该子类形成耦合时,就可以使用工厂方法模式来设计系统。工厂方法模式的关键是在一个接口或抽象类中定义一个抽象方法,该方法返回某个类的子类的实例,该抽象类或接口让其子类或实现该接口的类通过重写这个抽象方法返回某个子类的实例。二、工厂方法模式的结构与使用 2013-6-9 4 模式的结构中包括四种角色: ?抽象产品( Product Product Product Product ) ?具体产品( ConcreteProduct ConcreteProduct ConcreteProduct ConcreteProduct ) ?构造者( Creator Creator Creator Creator ) ?具体构造者( ConcreteCreator ConcreteCreator ConcreteCreator ConcreteCreator ) 2013-6-9 5 模式的 UML UML UML UML 类图 2013-6-9 6 模式的结构的描述与使用 1 1 1 1 .抽象产品( Product Product Product Product ) : : : : public abstract class PenCore{ public abstract class PenCore{ public abstract class PenCore{ public abstract class PenCore{ String color; String color; String color; String color; public abstract void writeWord(String s); public abstract void writeWord(String s);