Java设计模式-工厂方法模式

定义一个用于创建对象的接口，让子类决定将哪一个类实例化。Factory Method 使一个类的实例化延迟到其子类。

package car_interface;public interface Icar_interface {    public void start();    public void stop();}

package car_imple;import car_interface.Icar_interface;public class base_car_imple implements Icar_interface {    private int speed;    private String name;    public int getSpeed() {        return speed;    }    public void setSpeed(int speed) {        this.speed = speed;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public void start() {        // TODO Auto-generated method stub    }    public void stop() {        // TODO Auto-generated method stub    }}

package car_imple;import car_interface.Icar_interface;public class car_audi_imple extends base_car_imple {    public void start() {        System.out.println(this.getName() + " 车以专利技术起动了　最高速度为："                + this.getSpeed());    }    public void stop() {        System.out.println(this.getName() + " 车以专利技术停车了");    }}

package car_imple;import car_interface.Icar_interface;public class car_3w_imple extends base_car_imple {    public void start() {        System.out.println(this.getName() + " 车以专利技术起动了　最高速度为："                + this.getSpeed());    }    public void stop() {        System.out.println(this.getName() + " 车以专利技术停车了");    }}

package car_factory_interface;import car_interface.Icar_interface;public interface Icar_factory {    public Icar_interface create_car();}

package car_factory_imple;import car_factory_interface.Icar_factory;import car_imple.car_audi_imple;import car_interface.Icar_interface;public class audi_car_factory_imple implements Icar_factory {    public Icar_interface create_car() {        car_audi_imple car_audi_imple_ref = new car_audi_imple();        car_audi_imple_ref.setName("奥迪A6");        car_audi_imple_ref.setSpeed(300);        return car_audi_imple_ref;    }}

package car_factory_imple;import car_factory_interface.Icar_factory;import car_imple.car_3w_imple;import car_imple.car_audi_imple;import car_interface.Icar_interface;public class threeW_car_factory_imple implements Icar_factory {    public Icar_interface create_car() {        car_3w_imple car_3w_imple_ref = new car_3w_imple();        car_3w_imple_ref.setName("大众A6");        car_3w_imple_ref.setSpeed(400);        return car_3w_imple_ref;    }}

客户端运行程序代码：

package run_main;import car_factory_imple.audi_car_factory_imple;import car_factory_interface.Icar_factory;import car_interface.Icar_interface;public class run_main {    public static void main(String[] args) {        Icar_factory car_factory = new audi_car_factory_imple();        Icar_interface car_ref = car_factory.create_car();        car_ref.start();        car_ref.stop();    }}

 程序运行结果如下：

奥迪A6 车以专利技术起动了　最高速度为：300
奥迪A6 车以专利技术停车了

    通过使用工厂方法模式就可以将对象的创建延迟到子类进行实例化，而且每个工厂创建不同的品牌的汽车，每个汽车的功能都有自己“专利”的实现，这样可以将不同“品牌”的“汽车”的创建进行分类，有利于对象创建的清晰性。创建不同的汽车只需要改动这句代码就可以了：

Icar_factory car_factory = new audi_car_factory_imple();