大话设计模式4 简单工厂模式VS工厂模式

工厂模式：

与前面学习的简单工厂模式比起来，工厂模式更加符合开放封闭原则，新增对象类型是通过新增工厂类实现的，而非修改原有的工厂类。用一个简单的学雷锋的例子做对比。

package simpleFactoryVSFactory;interface IXueLeiFeng {    void sweep();    void wash();}class Student implements IXueLeiFeng {    @Override    public void sweep() {        // TODO Auto-generated method stub        System.out.println("Student sweep");    }    @Override    public void wash() {        // TODO Auto-generated method stub        System.out.println("Student wash");    }}class Volunteer implements IXueLeiFeng {    @Override    public void sweep() {        // TODO Auto-generated method stub        System.out.println("Volunteer sweep");    }    @Override    public void wash() {        // TODO Auto-generated method stub        System.out.println("Volunteer wash");    }}public class SimpleFactory {    public static IXueLeiFeng createLeiFeng(String name) {        IXueLeiFeng instance;        if (name.equals("student")) {            instance = new Student();        } else {            instance = new Volunteer();        }        return instance;    }    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        IXueLeiFeng leiFengA = createLeiFeng("student");        leiFengA.sweep();        leiFengA.wash();        IXueLeiFeng leiFengB = createLeiFeng("Not student");        leiFengB.sweep();        leiFengB.wash();    }}

工厂模式抽象出一个工厂接口，新增对象类型，只需要实现工厂接口，扩展即可。

package simpleFactoryVSFactory;interface IFactory {    IXueLeiFeng createLeiFeng();}class StudentFactory implements IFactory {    @Override    public IXueLeiFeng createLeiFeng() {        // TODO Auto-generated method stub        return new Student();    }}class VolunteerFactory implements IFactory {    @Override    public IXueLeiFeng createLeiFeng() {        // TODO Auto-generated method stub        return new Volunteer();    }}public class Factory {    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        IFactory iFactoryA = new StudentFactory();        IXueLeiFeng leiFengA = iFactoryA.createLeiFeng();        leiFengA.sweep();        leiFengA.wash();        IFactory iFactoryB = new VolunteerFactory();        IXueLeiFeng leiFengB = iFactoryB.createLeiFeng();        leiFengB.sweep();        leiFengB.wash();    }}

Head first

工厂模式VS抽象工厂

在Head first中,工厂模式:是定义了一个抽象方法,让继承它的子类去实现,将类的实例化推迟到子类.

而抽象工厂：则是定义了一个接口，里面组合了一堆相关对象的创建的方法。

工厂的特点：都是用来封装对象的创建，帮助实现针对接口编程，而非针对实现编程。