设计模式-工厂模式

工厂模式的定义

工厂模式使用的频率非常高，我们在开发中总能见到它们的身影。其定义为：
Define an interface for creating an object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses.

即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。工厂方法使一个类的实例化延迟到其子类
其相对于简单工厂模式,更加符合开闭原则!!!

工厂模式包括如下角色:

• 抽象产品
• 具体产品
• 抽象工厂
• 具体工厂

以上角色之间的关系如下图所示:

UML图如下:

java代码:

抽象产品（Abstract Product）角色

package com.gof.entity;/** *  * @ClassName: Audi * @Description: 奥迪车的图纸 * @author cheng * @date 2017-8-8 下午05:06:23 */public interface Audi {    /**     *      * @Title: desc     * @Description:用来描述汽车信息     */    void desc();}

具体产品（Concrete Product）角色

package com.gof.entity;/** *  * @ClassName: AudiA4 * @Description: 奥迪A4系列 * @author cheng * @date 2017-8-8 下午05:08:28 */public class AudiA4 implements Audi {    /**     * 重写     */    @Override    public void desc() {        System.out.println("我是一辆奥迪A4");    }}

package com.gof.entity;/** *  * @ClassName: AudiA6 * @Description: 奥迪A6系列 * @author cheng * @date 2017-8-8 下午05:16:17 */public class AudiA6 implements Audi {    /**     * 重写     */    @Override    public void desc() {        System.out.println("我是一辆奥迪A6");    }}

package com.gof.entity;/** *  * @ClassName: AudiA8 * @Description: 奥迪A8系列 * @author cheng * @date 2017-8-8 下午05:17:16 */public class AudiA8 implements Audi {    /**     * 重写     */    @Override    public void desc() {        System.out.println("我是一辆奥迪A8");    }}

抽象工厂（Abstract Factory）角色

package com.gof.factory1;import com.gof.entity.Audi;/** *  * @ClassName: AudiFactory * @Description: 生产奥迪的抽象工厂 * @author cheng * @date 2017-8-9 下午03:01:59 */public interface AudiFactory {    /**     *      * @Title: createAudi     * @Description:生产奥迪      * @return     */    Audi createAudi();}

具体工厂（Concrete Factory）角色

package com.gof.factory1;import com.gof.entity.Audi;import com.gof.entity.AudiA4;/** *  * @ClassName: AudiA4Factory * @Description: 奥迪A4生产工厂 * @author cheng * @date 2017-8-9 下午03:04:26 */public class AudiA4Factory implements AudiFactory{    /**     * 生产奥迪A4     */    @Override    public Audi createAudi() {        // TODO Auto-generated method stub        return new AudiA4();    }}

package com.gof.factory1;import com.gof.entity.Audi;import com.gof.entity.AudiA6;/** *  * @ClassName: AudiA6Factory * @Description: 奥迪A6生产工厂 * @author cheng * @date 2017-8-9 下午03:05:46 */public class AudiA6Factory implements AudiFactory {    /**     * 生产奥迪A6     */    @Override    public Audi createAudi() {        // TODO Auto-generated method stub        return new AudiA6();    }}

package com.gof.factory1;import com.gof.entity.Audi;import com.gof.entity.AudiA8;/** *  * @ClassName: AudiA8Factory * @Description: 奥迪A8生产工厂 * @author cheng * @date 2017-8-9 下午03:07:25 */public class AudiA8Factory implements AudiFactory {    /**     * 生产奥迪A8     */    @Override    public Audi createAudi() {        // TODO Auto-generated method stub        return new AudiA8();    }}

测试

package com.gof.factory1;import com.gof.entity.Audi;/** *  * @ClassName: AudiFactoryTest * @Description: 测试 * @author cheng * @date 2017-8-9 下午03:10:01 */public class AudiFactoryTest {    public static void main(String[] args){        System.out.println("====================================");        AudiFactory audiFactory1 = new AudiA4Factory();        Audi audi1 = audiFactory1.createAudi();        audi1.desc();        System.out.println("====================================");        AudiFactory audiFactory2 = new AudiA6Factory();        Audi audi2 = audiFactory2.createAudi();        audi2.desc();        System.out.println("====================================");        AudiFactory audiFactory3 = new AudiA8Factory();        Audi audi3 = audiFactory3.createAudi();        audi3.desc();    }}

运行结果