Php设计模式：行为型模式（二）_PHP_编程开发_程序员俱乐部

原文详见：http://www.ucai.cn/blogdetail/7023?mid=1&f=12

可以在线运行查看效果哦! ? ?

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<接上一篇>

4、观察者模式(Observer)：

? ? ? ? ?又叫发布订阅模式，当一个主体对象发生改变时，依赖它的多个观察者对象都得到通知并自动更新响应。就像报社一样，今天发布的消息只要是看这份报纸的人看到的都是同样的内容。如果发布另一份报纸，也是一样的。

???????? 好处：广播式通信，范围大，一呼百应，便于操作一个组团，“公有制”。

???????? 弊端：不能单独操作组团里的个体，不能实行按需分配。

? ? ? ? ?应用场景：操作多个对象，并操作相同。

代码实现：

?

?

class="dp-c">
1. <?php??
2. ??
3. /**?
4. ?*?优才网公开课示例代码?
5. ?*?
6. ?*?观察者模式?Observer?
7. ?*?
8. ?*?@author?优才网全栈工程师教研组?
9. ?*?@see?http://www.ucai.cn?
10. ?*/??
11. ??
12. function?output($string)?{??
13. ????echo????$string?.?"\n";??
14. }??
15. ??
16. ??
17. //订单数据对象简单模拟，这个是实际需要被观察的对象(Subject)，但是我们将其独立，然后??
18. //通过构造方法传入到我们模式中的Subject中，这样使具体业务更加独立??
19. class?Order{??
20. ????//订单号??
21. ????private?$id?=?'';??
22. ??
23. ????//用户ID??
24. ????private?$userId?=?'';??
25. ??
26. ????//用户名??
27. ????private?$userName?=?'';??
28. ??
29. ????//价格??
30. ????private?$price?=?'';??
31. ??
32. ????//下单时间??
33. ????private?$orderTime?=?'';??
34. ??
35. ????//订单数据填充简单模拟，实际应用中可能会读取用户表单输入并处理??
36. ????public?function?__set($name,?$value){??
37. ????????if?(isset($this->$name)){??
38. ????????????$this->$name?=?$value;??
39. ????????}??
40. ????}??
41. ??
42. ????//获取订单属性??
43. ????public?function?__get($name){??
44. ????????if?(isset($this->$name)){??
45. ????????????return?$this->$name;??
46. ????????}??
47. ????????return?"";??
48. ????}??
49. }??
50. ??
51. //假设的DB类，便于测试，实际会存入真实数据库??
52. class?FakeDB{??
53. ????public?function?save($data){??
54. ????????return?true;??
55. ????}??
56. }??
57. ??
58. ??
59. class?Client?{??
60. ??????
61. ????public?static?function?test()?{??
62. ??
63. ????????//初始化一个订单数据??
64. ????????$order?=?new?Order();??
65. ????????$order->id?=?1001;??
66. ????????$order->userId?=?9527;??
67. ????????$order->userName?=?"God";??
68. ????????$order->price?=?20.0;??
69. ????????$order->orderTime?=?time();??
70. ??
71. ????????//向数据库保存订单??
72. ????????$db?=?new?FakeDB();??
73. ????????$result?=?$db->save($order);??
74. ????????if?($result){??
75. ??
76. ????????????//实际应用可能会写到日志文件中，这里直接输出??
77. ????????????output(?"[OrderId:{$order->id}]?[UseId:{$order->userId}]?[Price:{$order->price}]"?);??
78. ??
79. ????????????//实际应用会调用邮件发送服务如sendmail，这里直接输出??
80. ????????????output(?"Dear?{$order->userName}:?Your?order?{$order->id}?was?confirmed!"?);??
81. ??
82. ????????????//实际应用会调用邮件发送服务如sendmail，这里直接输出??
83. ????????????output(?"Dear?Manager:?User?{$order->userName}(ID:{$order->userId})?submitted?a?new?order?{$order->id},?please?handle?it?ASAP!"?);??
84. ??
85. ????????}??
86. ??
87. ????}??
88. ??
89. }??
90. ??
91. Client::test();??
92. ??
93. ??
94. <?php??
95. ??
96. /**?
97. ?*?优才网公开课示例代码?
98. ?*?
99. ?*?观察者模式?Observer?
100. ?*?
101. ?*?@author?优才网全栈工程师教研组?
102. ?*?@see?http://www.ucai.cn?
103. ?*/??
104. ??
105. function?output($string)?{??
106. ????echo????$string?.?"\n";??
107. }??
108. ??
109. ??
110. //订单数据对象简单模拟，这个是实际需要被观察的对象(Subject)，但是我们将其独立，然后??
111. //通过构造方法传入到我们模式中的Subject中，这样使具体业务更加独立??
112. class?Order{??
113. ????//订单号??
114. ????private?$id?=?'';??
115. ??
116. ????//用户ID??
117. ????private?$userId?=?'';??
118. ??
119. ????//用户名??
120. ????private?$userName?=?'';??
121. ??
122. ????//价格??
123. ????private?$price?=?'';??
124. ??
125. ????//下单时间??
126. ????private?$orderTime?=?'';??
127. ??
128. ????//订单数据填充简单模拟，实际应用中可能会读取用户表单输入并处理??
129. ????public?function?__set($name,?$value){??
130. ????????if?(isset($this->$name)){??
131. ????????????$this->$name?=?$value;??
132. ????????}??
133. ????}??
134. ??
135. ????//获取订单属性??
136. ????public?function?__get($name){??
137. ????????if?(isset($this->$name)){??
138. ????????????return?$this->$name;??
139. ????????}??
140. ????????return?"";??
141. ????}??
142. }??
143. ??
144. //被观察者,?负责维护观察者并在变化发生是通知观察者??
145. class?OrderSubject?implements?SplSubject?{??
146. ????private?$observers;??
147. ????private?$order;??
148. ??
149. ????public?function?__construct(Order?$order)?{??
150. ????????$this->observers?=?new?SplObjectStorage();??
151. ????????$this->order?=?$order;??
152. ????}??
153. ??
154. ????//增加一个观察者??
155. ????public?function?attach(SplObserver?$observer)?{??
156. ????????$this->observers->attach($observer);??
157. ????}??
158. ??
159. ????//移除一个观察者??
160. ????public?function?detach(SplObserver?$observer)?{??
161. ????????$this->observers->detach($observer);??
162. ????}??
163. ??
164. ????//通知所有观察者??
165. ????public?function?notify()?{??
166. ????????foreach?($this->observers?as?$observer)?{??
167. ????????????$observer->update($this);??
168. ????????}??
169. ????}??
170. ??
171. ????//返回主体对象的具体实现，供观察者调用??
172. ????public?function?getOrder()?{??
173. ????????return?$this->order;??
174. ????}??
175. }??
176. ??
177. //记录业务数据日志?(ActionLogObserver)，实际可能还要抽象一层以处理不同的Action(业务操作)，这里省略??
178. class?ActionLogObserver?implements?SplObserver{??
179. ????public?function?update(SplSubject?$subject)?{??
180. ?????????$order?=?$subject->getOrder();??
181. ?????????//实际应用可能会写到日志文件中，这里直接输出??
182. ?????????output(?"[OrderId:{$order->id}]?[UseId:{$order->userId}]?[Price:{$order->price}]"?);??
183. ????}??
184. }??
185. ??
186. //给用户发送订单确认邮件?(UserMailObserver)??
187. class?UserMailObserver?implements?SplObserver{??
188. ????public?function?update(SplSubject?$subject)?{??
189. ?????????$order?=?$subject->getOrder();??
190. ?????????//实际应用会调用邮件发送服务如sendmail，这里直接输出??
191. ?????????output(?"Dear?{$order->userName}:?Your?order?{$order->id}?was?confirmed!"?);??
192. ????}??
193. }??
194. ??
195. //给管理人员发订单处理通知邮件?(AdminMailObserver)??
196. class?AdminMailObserver?implements?SplObserver{??
197. ????public?function?update(SplSubject?$subject)?{??
198. ?????????$order?=?$subject->getOrder();??
199. ?????????//实际应用会调用邮件发送服务如sendmail，这里直接输出??
200. ?????????output(?"Dear?Manager:?User?{$order->userName}(ID:{$order->userId})?submitted?a?new?order?{$order->id},?please?handle?it?ASAP!"?);??
201. ????}??
202. }??
203. ??
204. //假设的DB类，便于测试，实际会存入真实数据库??
205. class?FakeDB{??
206. ????public?function?save($data){??
207. ????????return?true;??
208. ????}??
209. }??
210. ??
211. ??
212. class?Client?{??
213. ??????
214. ????public?static?function?test()?{??
215. ??
216. ????????//初始化一个订单数据??
217. ????????$order?=?new?Order();??
218. ????????$order->id?=?1001;??
219. ????????$order->userId?=?9527;??
220. ????????$order->userName?=?"God";??
221. ????????$order->price?=?20.0;??
222. ????????$order->orderTime?=?time();??
223. ??
224. ????????//绑定观察者??
225. ????????$subject?=?new?OrderSubject($order);??
226. ????????$actionLogObserver?=?new?ActionLogObserver();??
227. ????????$userMailObserver?=?new?UserMailObserver();??
228. ????????$adminMailObserver?=?new?AdminMailObserver();??
229. ????????$subject->attach($actionLogObserver);??
230. ????????$subject->attach($userMailObserver);??
231. ????????$subject->attach($adminMailObserver);??
232. ????????//向数据库保存订单??
233. ????????$db?=?new?FakeDB();??
234. ????????$result?=?$db->save($order);??
235. ????????if?($result){??
236. ????????????//通知观察者??
237. ????????????$subject->notify();??
238. ????????}??
239. ??
240. ????}??
241. ??
242. }??
243. ??
244. Client::test();??

?

?

5、中介者模式(Mediator)：

? ? ? ? ?用中介对象封装一系列的对象交互，中介使各对象不需要显式地相互引用。类似于邮局，邮寄者和收件者不用自己跑很远路，通过邮局就可以。

? ? ? ? ?好处：简化了对象之间的关系，减少子类的生成。

? ? ? ? ?弊端：中介对象可能变得非常复杂，系统难以维护。

? ? ? ? ?应用场景：不需要显示地建立交互。

代码实现：

?

1. <?php??
2. ??
3. /**?
4. ?*?优才网公开课示例代码?
5. ?*?
6. ?*?中介者模式?Mediator?
7. ?*?
8. ?*?@author?优才网全栈工程师教研组?
9. ?*?@see?http://www.ucai.cn?
10. ?*/??
11. ??
12. ??
13. function?output($string)?{??
14. ????echo????$string?.?"\n";??
15. }??
16. ??
17. ??
18. ??
19. ??
20. abstract?class?Mediator?{?//?中介者角色??
21. ????abstract?public?function?send($message,$colleague);???
22. }???
23. ??
24. abstract?class?Colleague?{?//?抽象对象??
25. ????private?$_mediator?=?null;???
26. ????public?function?__construct($mediator)?{???
27. ????????$this->_mediator?=?$mediator;???
28. ????}???
29. ????public?function?send($message)?{???
30. ????????$this->_mediator->send($message,$this);???
31. ????}???
32. ????abstract?public?function?notify($message);???
33. }???
34. ??
35. class?ConcreteMediator?extends?Mediator?{?//?具体中介者角色??
36. ????private?$_colleague1?=?null;???
37. ????private?$_colleague2?=?null;???
38. ????public?function?send($message,$colleague)?{???
39. ????????if($colleague?==?$this->_colleague1)?{???
40. ????????????$this->_colleague1->notify($message);???
41. ????????}?else?{???
42. ????????????$this->_colleague2->notify($message);???
43. ????????}???
44. ????}??
45. ????public?function?set($colleague1,$colleague2)?{???
46. ????????$this->_colleague1?=?$colleague1;???
47. ????????$this->_colleague2?=?$colleague2;???
48. ????}???
49. }???
50. ??
51. class?Colleague1?extends?Colleague?{?//?具体对象角色??
52. ????public?function?notify($message)?{??
53. ????????output(sprintf('Colleague-1:?%s',?$message));??
54. ????}???
55. }???
56. ??
57. class?Colleague2?extends?Colleague?{?//?具体对象角色??
58. ????public?function?notify($message)?{???
59. ????????output(sprintf('Colleague-2:?%s',?$message));??
60. ????}???
61. }???
62. ??
63. ??
64. ??
65. class?Client?{????
66. ????????
67. ????public?static?function?test(){????
68. ??
69. ????????//?client??
70. ????????$objMediator?=?new?ConcreteMediator();???
71. ????????$objC1?=?new?Colleague1($objMediator);???
72. ????????$objC2?=?new?Colleague2($objMediator);???
73. ????????$objMediator->set($objC1,$objC2);???
74. ????????$objC1->send("to?c2?from?c1");???
75. ????????$objC2->send("to?c1?from?c2");???
76. ??
77. ????}????
78. ????????
79. }????
80. ????
81. Client::test();???

?

?

6、状态模式(State) ：

? ? ? ? ? 对象在不同状态下表现出不同的行为。就像女朋友一样，高兴了牵你的手，不高兴了遛狗。在两种状态下变现出不同的行为。

? ? ? ? ?好处：避免if语句实用，方便增加新状态，封装了状态转换规则。

? ? ? ? ?弊端：增加系统类和对象的数量。

? ? ? ? ?应用场景：用于对象的不同功能的转换。

代码实现：

?

1. <?php??
2. ??
3. /**?
4. ?*?优才网公开课示例代码?
5. ?*?
6. ?*?状态模式?State?
7. ?*?
8. ?*?@author?优才网全栈工程师教研组?
9. ?*?@see?http://www.ucai.cn?
10. ?*/??
11. ??
12. function?output($string)?{??
13. ????echo????$string?.?"\n";??
14. }??
15. ??
16. abstract?class?ILift?{????
17. ??
18. ????//电梯的四个状态????
19. ????const?OPENING_STATE?=?1;??//门敞状态????
20. ????const?CLOSING_STATE?=?2;??//门闭状态????
21. ????const?RUNNING_STATE?=?3;??//运行状态????
22. ????const?STOPPING_STATE?=?4;?//停止状态；????
23. ????????
24. ????//设置电梯的状态????
25. ????public?abstract?function?setState($state);????
26. ????
27. ????//首先电梯门开启动作????
28. ????public?abstract?function?open();????
29. ????
30. ????//电梯门有开启，那当然也就有关闭了????
31. ????public?abstract?function?close();????
32. ????
33. ????//电梯要能上能下，跑起来????
34. ????public?abstract?function?run();????
35. ????
36. ????//电梯还要能停下来??
37. ????public?abstract?function?stop();????
38. ??
39. }????
40. ????
41. /**??
42. ?*?电梯的实现类???
43. ?*/?????
44. class?Lift?extends?ILift?{????
45. ??
46. ????private?$state;????
47. ????
48. ????public?function?setState($state)?{????
49. ????????$this->state?=?$state;????
50. ????}????
51. ??
52. ????//电梯门关闭????
53. ????public?function?close()?{????
54. ??
55. ????????//电梯在什么状态下才能关闭????
56. ????????switch?($this->state)?{????
57. ????????????case?ILift::OPENING_STATE:??//如果是则可以关门，同时修改电梯状态????
58. ????????????????$this->setState(ILift::CLOSING_STATE);????
59. ????????????break;????
60. ????????????case?ILift::CLOSING_STATE:??//如果电梯就是关门状态，则什么都不做????
61. ????????????????//do?nothing;????
62. ????????????????return?;????
63. ????????????break;????
64. ????????????case?ILift::RUNNING_STATE:?//如果是正在运行，门本来就是关闭的，也说明都不做????
65. ????????????????//do?nothing;????
66. ????????????????return?;????
67. ????????????break;????
68. ????????????case?ILift::STOPPING_STATE:??//如果是停止状态，本也是关闭的，什么也不做????
69. ????????????????//do?nothing;????
70. ????????????????return?;????
71. ????????????break;????
72. ????????}????
73. ??
74. ????????output('Lift?colse');????
75. ??
76. ????}????
77. ????
78. ????//电梯门开启????
79. ????public?function?open()?{????
80. ????????//电梯在什么状态才能开启????
81. ????????switch($this->state){????
82. ????????????case?ILift::OPENING_STATE:?//如果已经在门敞状态，则什么都不做????
83. ????????????????//do?nothing;????
84. ????????????????return?;????
85. ????????????break;????
86. ????????????case?ILift::CLOSING_STATE:?//如是电梯时关闭状态，则可以开启????
87. ????????????????$this->setState(ILift::OPENING_STATE);????
88. ????????????break;????
89. ????????????case?ILift::RUNNING_STATE:?//正在运行状态，则不能开门，什么都不做????
90. ????????????//do?nothing;????
91. ????????????????return?;????
92. ????????????break;????
93. ????????????case?ILift::STOPPING_STATE:?//停止状态，淡然要开门了????
94. ????????????????$this->setState(ILift::OPENING_STATE);????
95. ????????????break;????
96. ????????}????
97. ????????output('Lift?open');????
98. ????}????
99. ????///电梯开始跑起来????
100. ????public?function?run()?{????
101. ????????switch($this->state){????
102. ????????????case?ILift::OPENING_STATE:?//如果已经在门敞状态，则不你能运行，什么都不做????
103. ????????????????//do?nothing;????
104. ????????????????return?;????
105. ????????????break;????
106. ????????????case?ILift::CLOSING_STATE:?//如是电梯时关闭状态，则可以运行????
107. ????????????????$this->setState(ILift::RUNNING_STATE);????
108. ????????????break;????
109. ????????????case?ILift::RUNNING_STATE:?//正在运行状态，则什么都不做????
110. ????????????????//do?nothing;????
111. ????????????????return?;????
112. ????????????break;????
113. ????????????case?ILift::STOPPING_STATE:?//停止状态，可以运行????
114. ????????????????$this->setState(ILift::RUNNING_STATE);????
115. ????????}????
116. ????????output('Lift?run');????
117. ????}????
118. ????
119. ????//电梯停止????
120. ????public?function?stop()?{????
121. ????????switch($this->state){????
122. ????????????case?ILift::OPENING_STATE:?//如果已经在门敞状态，那肯定要先停下来的，什么都不做????
123. ????????????????//do?nothing;????
124. ????????????????return?;????
125. ????????????break;????
126. ????????????case?ILift::CLOSING_STATE:?//如是电梯时关闭状态，则当然可以停止了????
127. ????????????????$this->setState(ILift::CLOSING_STATE);????
128. ????????????break;????
129. ????????????case?ILift::RUNNING_STATE:?//正在运行状态，有运行当然那也就有停止了????
130. ????????????????$this->setState(ILift::CLOSING_STATE);????
131. ????????????break;????
132. ????????????case?ILift::STOPPING_STATE:?//停止状态，什么都不做????
133. ????????????????//do?nothing;????
134. ????????????????return?;????
135. ????????????break;????
136. ????????}????
137. ????????output('Lift?stop');????
138. ????}????
139. ????????
140. }????
141. ??
142. ??
143. ??
144. class?Client?{??
145. ??????
146. ????public?static?function?test()?{??
147. ??
148. ????????$lift?=?new?Lift();?????
149. ???????????????
150. ????????//电梯的初始条件应该是停止状态?????
151. ????????$lift->setState(ILift::STOPPING_STATE);?????
152. ????????//首先是电梯门开启，人进去?????
153. ????????$lift->open();?????
154. ???????????????
155. ????????//然后电梯门关闭?????
156. ????????$lift->close();?????
157. ???????????????
158. ????????//再然后，电梯跑起来，向上或者向下?????
159. ????????$lift->run();????????
160. ??
161. ?????????//最后到达目的地，电梯挺下来?????
162. ????????$lift->stop();????
163. ??
164. ????}??
165. ??
166. }??
167. ??
168. Client::test();??
169. ??
170. ??
171. <?php??
172. ??
173. /**?
174. ?*?优才网公开课示例代码?
175. ?*?
176. ?*?状态模式?State?
177. ?*?
178. ?*?@author?优才网全栈工程师教研组?
179. ?*?@see?http://www.ucai.cn?
180. ?*/??
181. ??
182. function?output($string)?{??
183. ????echo????$string?.?"\n";??
184. }??
185. ??
186. /**??
187. ?*???
188. ?*?定义一个电梯的接口???
189. ?*/?????
190. abstract?class?LiftState{????
191. ????
192. ????//定义一个环境角色，也就是封装状态的变换引起的功能变化????
193. ????protected??$_context;????
194. ????
195. ????public?function?setContext(Context?$context){????
196. ????????$this->_context?=?$context;????
197. ????}????
198. ????
199. ????//首先电梯门开启动作????
200. ????public?abstract?function?open();????
201. ????
202. ????//电梯门有开启，那当然也就有关闭了????
203. ????public?abstract?function?close();????
204. ????
205. ????//电梯要能上能下，跑起来????
206. ????public?abstract?function?run();????
207. ????
208. ????//电梯还要能停下来，停不下来那就扯淡了????
209. ????public?abstract?function?stop();????
210. ????
211. }????
212. ????
213. ????
214. /**??
215. ?*?环境类:定义客户感兴趣的接口。维护一个ConcreteState子类的实例，这个实例定义当前状态。??
216. ?*/?????
217. class?Context?{????
218. ????//定义出所有的电梯状态????
219. ????static??$openningState?=?null;????
220. ????static??$closeingState?=?null;????
221. ????static??$runningState??=?null;????
222. ????static??$stoppingState?=?null;????
223. ????
224. ????public?function?__construct()?{????
225. ????????self::$openningState?=?new?OpenningState();????
226. ????????self::$closeingState?=?new?ClosingState();????
227. ????????self::$runningState?=??new?RunningState();????
228. ????????self::$stoppingState?=?new?StoppingState();????
229. ????
230. ????}????
231. ????
232. ????//定一个当前电梯状态????
233. ????private??$_liftState;????
234. ????
235. ????public?function?getLiftState()?{????
236. ????????return?$this->_liftState;????
237. ????}????
238. ????
239. ????public?function?setLiftState($liftState)?{????
240. ????????$this->_liftState?=?$liftState;????
241. ????????//把当前的环境通知到各个实现类中????
242. ????????$this->_liftState->setContext($this);????
243. ????}????
244. ????
245. ????
246. ????public?function?open(){????
247. ????????$this->_liftState->open();????
248. ????}????
249. ????
250. ????public?function?close(){????
251. ????????$this->_liftState->close();????
252. ????}????
253. ????
254. ????public?function?run(){????
255. ????????$this->_liftState->run();????
256. ????}????
257. ????
258. ????public?function?stop(){????
259. ????????$this->_liftState->stop();????
260. ????}????
261. }????
262. ????
263. /**??
264. ?*?在电梯门开启的状态下能做什么事情???
265. ?*/?????
266. class?OpenningState?extends?LiftState?{????
267. ????
268. ????/**??
269. ?????*?开启当然可以关闭了，我就想测试一下电梯门开关功能??
270. ?????*??
271. ?????*/????
272. ????public?function?close()?{????
273. ????????//状态修改????
274. ????????$this->_context->setLiftState(Context::$closeingState);????
275. ????????//动作委托为CloseState来执行????
276. ????????$this->_context->getLiftState()->close();????
277. ????}????
278. ????
279. ????//打开电梯门????
280. ????public?function?open()?{????
281. ????????output('lift?open...');??
282. ????}????
283. ????//门开着电梯就想跑，这电梯，吓死你！????
284. ????public?function?run()?{????
285. ????????//do?nothing;????
286. ????}????
287. ????
288. ????//开门还不停止？????
289. ????public?function?stop()?{????
290. ????????//do?nothing;????
291. ????}????
292. ????
293. }????
294. ????
295. /**??
296. ?*?电梯门关闭以后，电梯可以做哪些事情???
297. ?*/?????
298. class?ClosingState?extends?LiftState?{????
299. ????
300. ????//电梯门关闭，这是关闭状态要实现的动作????
301. ????public?function?close()?{????
302. ????????output('lift?close...');??
303. ????
304. ????}????
305. ????//电梯门关了再打开，逗你玩呢，那这个允许呀????
306. ????public?function?open()?{????
307. ????????$this->_context->setLiftState(Context::$openningState);??//置为门敞状态????
308. ????????$this->_context->getLiftState()->open();????
309. ????}????
310. ????
311. ????//电梯门关了就跑，这是再正常不过了????
312. ????public?function?run()?{????
313. ????????$this->_context->setLiftState(Context::$runningState);?//设置为运行状态；????
314. ????????$this->_context->getLiftState()->run();????
315. ????}????
316. ????
317. ????//电梯门关着，我就不按楼层????
318. ????????
319. ????public?function?stop()?{????
320. ????????$this->_context->setLiftState(Context::$stoppingState);??//设置为停止状态；????
321. ????????$this->_context->getLiftState()->stop();????
322. ????}????
323. ????
324. }????
325. ????
326. /**??
327. ?*?电梯在运行状态下能做哪些动作???
328. ?*/?????
329. class?RunningState?extends?LiftState?{????
330. ????
331. ????//电梯门关闭？这是肯定了????
332. ????public?function?close()?{????
333. ????????//do?nothing????
334. ????}????
335. ????
336. ????//运行的时候开电梯门？你疯了！电梯不会给你开的????
337. ????public?function?open()?{????
338. ????????//do?nothing????
339. ????}????
340. ????
341. ????//这是在运行状态下要实现的方法????
342. ????public?function?run()?{????
343. ????????output('lift?run...');??
344. ????}????
345. ????
346. ????//这个事绝对是合理的，光运行不停止还有谁敢做这个电梯？！估计只有上帝了????
347. ????public?function?stop()?{????
348. ????????$this->_context->setLiftState(Context::$stoppingState);?//环境设置为停止状态；????
349. ????????$this->_context->getLiftState()->stop();????
350. ????}????
351. ????
352. }????
353. ????
354. ????
355. ????
356. /**??
357. ?*?在停止状态下能做什么事情???
358. ?*/?????
359. class?StoppingState?extends?LiftState?{????
360. ????
361. ????//停止状态关门？电梯门本来就是关着的！????
362. ????public?function?close()?{????
363. ????????//do?nothing;????
364. ????}????
365. ????
366. ????//停止状态，开门，那是要的！????
367. ????public?function?open()?{????
368. ????????$this->_context->setLiftState(Context::$openningState);????
369. ????????$this->_context->getLiftState()->open();????
370. ????}????
371. ????//停止状态再跑起来，正常的很????
372. ????public?function?run()?{????
373. ????????$this->_context->setLiftState(Context::$runningState);????
374. ????????$this->_context->getLiftState()->run();????
375. ????}????
376. ????//停止状态是怎么发生的呢？当然是停止方法执行了????
377. ????public?function?stop()?{????
378. ????????output('lift?stop...');??
379. ????}????
380. ????
381. }????
382. ????
383. /**??
384. ?*?模拟电梯的动作???
385. ?*/?????
386. class?Client?{????
387. ????
388. ????public?static?function?test()?{????
389. ????????$context?=?new?Context();????
390. ????????$context->setLiftState(new?ClosingState());????
391. ????
392. ????????$context->open();????
393. ????????$context->close();????
394. ????????$context->run();????
395. ????????$context->stop();????
396. ????}????
397. }????
398. ??
399. Client::test(); ??