简单工厂

一、适用场景

1）工厂类负责创建的对象比较少

2）客户端（应用层）只知道传入工厂类的参数，对于如何创建对象（逻辑）不关心

二、优点

只需要传入一个正确的参数，就可以获得你想要的对象，而无需知道细节

三、缺点

工厂类的职责相对过重，增加新的产品需要修改工厂类的判断逻辑

四、代码

1）

public abstract class Video { public abstract void produce(); } public class JavaVideo extends Video { @Override public void produce() { System.out.println("java video!"); } } public class PythonVideo extends Video{ @Override public void produce() { System.out.println("python video!"); } } public class VideoFactory { public Video getVideo(String type){ if(type == "java"){ return new JavaVideo(); }else if(type == "python"){ return new PythonVideo(); } return null; } } public class Test { /** * @param args */ public static void main(String[] args) { VideoFactory videoFactory = new VideoFactory(); Video video = videoFactory.getVideo("java"); video.produce(); } }

2）第二种方式

public class VideoFactory { public Video getVideo(Class c){ Video video = null; try { video = (Video)Class.forName(c.getName()).newInstance(); } catch (InstantiationException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalAccessException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } return video; } } public class Test { /** * @param args */ public static void main(String[] args) { VideoFactory videoFactory = new VideoFactory(); Video video = videoFactory.getVideo(JavaVideo.class); video.produce(); } }