外观模式 - 润新知

外观模式
外观模式：http://www.javaeye.com/topic/327449
定义：它为子系统中的一组接口提供一个统一的高层接口。是的子系统更容易使用。

有一天女朋友想要去一个地方旅游。。旅游需要考虑很多很多的问题。如旅游的地点，航班，宾馆，饭店。我把所有的这些问题都扔给她了。。。假设简化旅游的行程。需要完成的步骤有
- 计划旅游景点
- 预定宾馆
- 预定机票
- 飞往目的地
- 入住宾馆
- 吃饭
- 游玩
首先把旅游作为一个子系统，子系统包含4个类，分别如下。
航班Java代码
1. package facade.demo;
2. /**
3. * 航班
4. * @author Nicholas
5. *
6. */
7. public class Flight {
8. public void scheduled(){
9. System.out.println("预定机票");
10. }
12. public void go(){
13. System.out.println("飞往目的地");
14. }
15. }
package facade.demo; /** * 航班 * @author Nicholas * */ public class Flight { public void scheduled(){ System.out.println("预定机票"); } public void go(){ System.out.println("飞往目的地"); } }
package facade.demo; /** * 饭店 * @author Nicholas * */ public class Restaurant { public void eating(){ System.out.println("吃饭"); } }
好了。。旅游真是个麻烦事情，我还是把这些麻烦扔给女朋友吧。。
女朋友Java代码 <embed height="15" width="14" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" allowscriptaccess="always" quality="high" flashvars="clipboard=package%20facade.demo%3B%0A%2F**%0A%20*%20%E6%88%91%E7%9A%84%E5%A5%B3%E6%9C%8B%E5%8F%8B%0A%20*%20%40author%20Nicholas%0A%20*%0A%20*%2F%0Apublic%20class%20Mygirl1%20%7B%0A%09private%20Flight%20flight%3B%0A%09private%20Hotel%20hotel%3B%0A%09private%20Place%20place%3B%0A%09private%20Restaurant%20restaurant%3B%0A%0A%09%0A%09public%20Mygirl1(Flight%20flight%2C%20Hotel%20hotel%2C%20Place%20place%2C%20Restaurant%20restaurant)%20%7B%0A%09%09this.flight%20%3D%20flight%3B%0A%09%09this.hotel%20%3D%20hotel%3B%0A%09%09this.place%20%3D%20place%3B%0A%09%09this.restaurant%20%3D%20restaurant%3B%0A%09%7D%0A%09%0A%09%0A%09public%20void%20travel()%7B%0A%09%09place.plan()%3B%0A%09%09hotel.booking()%3B%0A%09%09flight.scheduled()%3B%0A%09%09flight.go()%3B%0A%09%09hotel.check()%3B%0A%09%09restaurant.eating()%3B%0A%09%09place.play()%3B%0A%09%7D%0A%09%0A%09public%20static%20void%20main(String%5B%5D%20args)%7B%0A%09%09Flight%20flight%20%3D%20new%20Flight()%3B%0A%09%09Hotel%20hotel%20%3D%20new%20Hotel()%3B%0A%09%09Place%20place%20%3D%20new%20Place()%3B%0A%09%09Restaurant%20restaurant%20%3D%20new%20Restaurant()%3B%0A%09%09Mygirl1%20mygirl%20%3D%20new%20Mygirl1(flight%2Chotel%2Cplace%2Crestaurant)%3B%0A%09%09mygirl.travel()%3B%0A%09%09%0A%09%7D%0A%09%0A%7D%0A%0A" src="http://www.javaeye.com/javascripts/syntaxhighlighter/clipboard_new.swf" lk_mediaid="lk_juiceapp_mediaPopup_1235113984027" lk_media="yes">
1. package facade.demo;
2. /**
3. * 我的女朋友
4. * @author Nicholas
5. *
6. */
7. public class Mygirl1 {
8. private Flight flight;
9. private Hotel hotel;
10. private Place place;
11. private Restaurant restaurant;
14. public Mygirl1(Flight flight, Hotel hotel, Place place, Restaurant restaurant) {
15. this.flight = flight;
16. this.hotel = hotel;
17. this.place = place;
18. this.restaurant = restaurant;
19. }
22. public void travel(){
23. place.plan();
24. hotel.booking();
25. flight.scheduled();
26. flight.go();
27. hotel.check();
28. restaurant.eating();
29. place.play();
30. }
32. public static void main(String[] args){
33. Flight flight = new Flight();
34. Hotel hotel = new Hotel();
35. Place place = new Place();
36. Restaurant restaurant = new Restaurant();
37. Mygirl1 mygirl = new Mygirl1(flight,hotel,place,restaurant);
38. mygirl.travel();
40. }
42. }
package facade.demo; /** * 我的女朋友 * @author Nicholas * */ public class Mygirl1 { private Flight flight; private Hotel hotel; private Place place; private Restaurant restaurant; public Mygirl1(Flight flight, Hotel hotel, Place place, Restaurant restaurant) { this.flight = flight; this.hotel = hotel; this.place = place; this.restaurant = restaurant; } public void travel(){ place.plan(); hotel.booking(); flight.scheduled(); flight.go(); hotel.check(); restaurant.eating(); place.play(); } public static void main(String[] args){ Flight flight = new Flight(); Hotel hotel = new Hotel(); Place place = new Place(); Restaurant restaurant = new Restaurant(); Mygirl1 mygirl = new Mygirl1(flight,hotel,place,restaurant); mygirl.travel(); } }
结果如下：
计划旅游景点
预定宾馆
预定机票
飞往目的地
入住宾馆
吃饭
游玩

以上都是我的想象了。。。女朋友就是上帝啊。。。。。哎。如果真的那样做。。估计女朋友非弄死我。。。
到这里我们发现了个问题。女朋友要旅游需要关心那么多问题。。这些对她来说太复杂了。。她并不关心细节。只要她答到旅游的目的就好了。。。这时候，解决麻烦的人出现了。。。对，那就好我，我就是那个所谓的"外观"。我来把这些问题解决掉，让她享受旅游的过程就好了。
我Java代码 <embed height="15" width="14" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" allowscriptaccess="always" quality="high" flashvars="clipboard=package%20facade.demo%3B%0A%0A%2F**%0A%20*%20%E6%88%91(%E6%88%91%E5%B0%B1%E6%98%AF%E5%A4%96%E8%A7%82%E4%BA%86)%0A%20*%20%40author%20Nicholas%0A%20*%0A%20*%2F%0Apublic%20class%20ManFacade%20%7B%0A%09private%20Flight%20flight%3B%0A%09private%20Hotel%20hotel%3B%0A%09private%20Place%20place%3B%0A%09private%20Restaurant%20restaurant%3B%0A%0A%20%20%20%20%20%20%20public%20ManFacade()%7B%20%20%20%20%20%0A%20%20%20%20%20%20%20%20%20%20%20%20%20%20this.flight%20%3D%20new%20Flight()%3B%0A%09%09this.hotel%20%3D%20new%20Hotel()%3B%0A%09%09this.place%20%3D%20new%20Place()%3B%0A%09%09this.restaurant%20%3D%20new%20Restaurant()%3B%0A%20%20%20%20%20%20%26nbsp%3B%7D%0A%0A%09public%20ManFacade(Flight%20flight%2C%20Hotel%20hotel%2C%20Place%20place%2C%20Restaurant%20restaurant)%20%7B%0A%09%09this.flight%20%3D%20flight%3B%0A%09%09this.hotel%20%3D%20hotel%3B%0A%09%09this.place%20%3D%20place%3B%0A%09%09this.restaurant%20%3D%20restaurant%3B%0A%09%7D%0A%09%0A%09%0A%09public%20void%20travel()%7B%0A%09%09place.plan()%3B%0A%09%09hotel.booking()%3B%0A%09%09flight.scheduled()%3B%0A%09%09flight.go()%3B%0A%09%09hotel.check()%3B%0A%09%09restaurant.eating()%3B%0A%09%09place.play()%3B%0A%09%7D%0A%7D%0A" src="http://www.javaeye.com/javascripts/syntaxhighlighter/clipboard_new.swf" lk_mediaid="lk_juiceapp_mediaPopup_1235113984029" lk_media="yes">
1. package facade.demo;
3. /**
4. * 我(我就是外观了)
5. * @author Nicholas
6. *
7. */
8. public class ManFacade {
9. private Flight flight;
10. private Hotel hotel;
11. private Place place;
12. private Restaurant restaurant;
14. public ManFacade(){
15. this.flight = new Flight();
16. this.hotel = new Hotel();
17. this.place = new Place();
18. this.restaurant = new Restaurant();
19. }
21. public ManFacade(Flight flight, Hotel hotel, Place place, Restaurant restaurant) {
22. this.flight = flight;
23. this.hotel = hotel;
24. this.place = place;
25. this.restaurant = restaurant;
26. }
29. public void travel(){
30. place.plan();
31. hotel.booking();
32. flight.scheduled();
33. flight.go();
34. hotel.check();
35. restaurant.eating();
36. place.play();
37. }
38. }
package facade.demo; /** * 我(我就是外观了) * @author Nicholas * */ public class ManFacade { private Flight flight; private Hotel hotel; private Place place; private Restaurant restaurant; public ManFacade(){ this.flight = new Flight(); this.hotel = new Hotel(); this.place = new Place(); this.restaurant = new Restaurant(); } public ManFacade(Flight flight, Hotel hotel, Place place, Restaurant restaurant) { this.flight = flight; this.hotel = hotel; this.place = place; this.restaurant = restaurant; } public void travel(){ place.plan(); hotel.booking(); flight.scheduled(); flight.go(); hotel.check(); restaurant.eating(); place.play(); } }
看来麻烦解决掉了。女朋友很轻松的享受旅游过程了。。。。
Java代码
1. package facade.demo;
3. /**
4. * 女朋友
5. * @author Nicholas
6. *
7. */
8. public class Mygirl {
10. public static void main(String[] args){
11. Restaurant restaurant = new Restaurant();
12. ManFacade manFacade = new ManFacade();//我来解决掉这些麻烦。。。
13. manFacade.travel();//旅游成功
14. }
16. }
package facade.demo; /** * 女朋友 * @author Nicholas * */ public class Mygirl { public static void main(String[] args){ Restaurant restaurant = new Restaurant(); ManFacade manFacade = new ManFacade();//我来解决掉这些麻烦。。。 manFacade.travel();//旅游成功 } }
结果如下：
计划旅游景点
预定宾馆
预定机票
飞往目的地
入住宾馆
吃饭
游玩

本身外观模式的作用就是让接口更容易使用。真实的场景要复杂的多，这个例子只能提供个表面的意思。
总的来说，外观模式就是为了使接口更简单。。。
相关阅读:
身份证相关类
 微信开发相关文档
 password、文件MD5加密，passwordsha256、sha384、sha512Hex等加密
 图的割点（边表集实现）
动态库DLL中类的使用
 吴恩达机器学习笔记_第三周
 Android官方开发文档Training系列课程中文版：性能优化建议
 简单算法汇总
 Gson解析第三方提供Json数据（天气预报，新闻等）
Java字节码小结
原文地址：https://www.cnblogs.com/danghuijian/p/4400716.html