php教程分享

  1. php教程首页
  2. php面向对象

PHP设计模式入门之状态模式原理与实现方法分析

•php面向对象•阅读 428

本文实例讲述了PHP设计模式入门之状态模式原理与实现方法，分享给大家供大家参考，具体如下：

想必大家都用过自动售卖的自动饮料机吧，塞入硬币或纸币，选择想要的饮料，饮料就会在机器的下方滚出。大家有没有相关如果用程序去写一个饮料机要怎么样实现呢？

首先我们可以分享一下这部饮料机有几种状态

一、没有钱的状态

二、有钱的状态

三、售出的状态

四、销售一空的状态

好吧，知道了这些状态之后我们开始写代码了！

JuiceMachine.php

  1. <?php
  2. /**
  3. * 饮料机
  4. * @author ben
  5. *
  6. */
  7. class JuiceMachine{
  8. /**
  9. * 糖果机一共存在四种状态：没钱，有钱，成功售出以及销售一空
  10. *
  11. * 没钱的状态
  12. * @var INT
  13. */
  14. const NOMONEY = 0;
  15. /**
  16. * 有钱的状态
  17. * @var INT
  18. */
  19. const HASMONEY = 1;
  20. /**
  21. * 成功售出的状态
  22. * @var INT
  23. */
  24. const SOLD = 2;
  25. /**
  26. * 销售一空的状态
  27. * @var INT
  28. */
  29. const SOLDOUT = 3;
  30. /**
  31. * 记录糖果机当前的状态，初始化状态为售空
  32. * @var INT
  33. */
  34. private $_state = JuiceMachine::SOLDOUT;
  35. /**
  36. * 该变量用于记录饮料机中饮料的数量
  37. */
  38. private $_count;
  39. /**
  40. * 构造方法，最主要是用来初始化count和state属性的
  41. */
  42. public function __construct($count){
  43. $this->_count = $count;
  44. //当饮料机中的饮料数量大于零时，将饮料机的状态重置为没有钱的状态。
  45. if($this->_count > 0){
  46. $this->_state = JuiceMachine::NOMONEY;
  47. }
  48. }
  49. /**
  50. * 投入硬币
  51. */
  52. public function insertCoin(){
  53. if($this->_state == JuiceMachine::HASMONEY ){
  54. echo "you can't insert another coin!<br />";
  55. }elseif($this->_state == JuiceMachine::NOMONEY){
  56. echo "you just insert a coin<br />";
  57. $this->_state = JuiceMachine::HASMONEY;
  58. }elseif($this->_state == JuiceMachine::SOLD){
  59. echo "wait a minute, we are giving you a bottle of juice<br />";
  60. }elseif($this->_state == JuiceMachine::SOLDOUT){
  61. echo "you can't insert coin, the machine is already soldout<br />";
  62. }
  63. }
  64. /**
  65. * 退回硬币
  66. */
  67. public function retreatCoin(){
  68. if($this->_state == JuiceMachine::HASMONEY ){
  69. echo "coin return!<br />";
  70. $this->_state = JuiceMachine::NOMONEY;
  71. }elseif($this->_state == JuiceMachine::NOMONEY){
  72. echo "you have'nt inserted a coin yet<br />";
  73. }elseif($this->_state == JuiceMachine::SOLD){
  74. echo "sorry, you already clicked the botton<br />";
  75. }elseif($this->_state == JuiceMachine::SOLDOUT){
  76. echo "you have'nt inserted a coin yet<br />";
  77. }
  78. }
  79. /**
  80. * 点击饮料对应的按钮
  81. */
  82. public function clickButton(){
  83. if($this->_state == JuiceMachine::HASMONEY ){
  84. echo "you clicked, we are giving you a bottle of juice...<br />";
  85. $this->_state = JuiceMachine::SOLD; //改变饮料机的状态为售出模式
  86. $this->dispend();
  87. }elseif($this->_state == JuiceMachine::NOMONEY){
  88. echo "you clicked,but you hav'nt inserted a coin yet<br />";
  89. }elseif($this->_state == JuiceMachine::SOLD){
  90. echo "click twice does'nt get you two bottle of juice<br />";
  91. }elseif($this->_state == JuiceMachine::SOLDOUT){
  92. echo "you clicked, but the machine is already soldout<br />";
  93. }
  94. }
  95. /**
  96. * 发放饮料
  97. */
  98. public function dispend(){
  99. if($this->_state == JuiceMachine::HASMONEY ){
  100. echo "please click the button first<br />";
  101. }elseif($this->_state == JuiceMachine::NOMONEY){
  102. echo "you need to pay first<br />";
  103. }elseif($this->_state == JuiceMachine::SOLD){
  104. echo "now you get you juice<br />";
  105. //饮料机中的饮料数量减一
  106. $this->_count--;
  107. if($this->_count <= 0){
  108. echo "opps, runing out of juice<br />";
  109. //如果这时饮料机中没有饮料了，将饮料机的状态重置为销售一空
  110. $this->_state = JuiceMachine::SOLDOUT;
  111. }else{
  112. //将饮料机的状态重置为没有钱
  113. $this->_state = JuiceMachine::NOMONEY;
  114. }
  115. }elseif($this->_state == JuiceMachine::SOLDOUT){
  116. //其实这种情况不应该出现
  117. echo "opps, it appears that we don't have any juice left<br />";
  118. }
  119. }
  120. }

index.php

  1. <?php
  2. require_once 'JuiceMachine.php';
  3. $juiceMachine = new JuiceMachine(1);
  4. $juiceMachine->insertCoin();
  5. $juiceMachine->clickButton();

运行的结果是：

you just insert a coin

you clicked, we are giving you a bottle of juice...

now you get you juice

opps, runing out of juice

到目前为止我们的程序运行良好，没有出现什么问题，但是从这些多重的if判断中你是否嗅到了坏代码的味道呢？有一天问题终于出现了，老板希望当用户点击按钮时有10%的概率拿到两瓶饮料，我们需要为饮料机多加一个状态，这时去修改代码就成为了一种灾难，而且很可能会影响到之前的代码，带来新的bug，看看状态模式如何帮助我们度过难关吧！

状态模式的官方定义是：状态模式允许对象在内部状态改变是改变它的行为，对象看起来好像是修改了它的类

用uml类图表示如下：

在我们这个项目中的实际类图如下：

具体实现代码：

State.php

  1. <?php
  2. interface State{
  3. /**
  4. * 插入硬币
  5. */
  6. public function insertCoin();
  7. /**
  8. * 回退硬币
  9. */
  10. public function retreatCoin();
  11. /**
  12. * 点击按钮
  13. */
  14. public function clickButton();
  15. /**
  16. * 发放饮料
  17. */
  18. public function dispend();
  19. }

NomoneyState.php

  1. <?php
  2. require_once 'State.php';
  3. class NomoneyState implements State{
  4. /**
  5. * 饮料机的实例
  6. *
  7. * @var object
  8. */
  9. private $_juiceMachine;
  10. /**
  11. * 构造方法，主要用于初始化饮料机实例
  12. *
  13. */
  14. public function __construct($juiceMachine){
  15. $this->_juiceMachine = $juiceMachine;
  16. }
  17. /* (non-PHPdoc)
  18. * @see State::insertCoin()
  19. */
  20. public function insertCoin()
  21. {
  22. // TODO Auto-generated method stub
  23. echo "you just insert a coin<br />";
  24. //将饮料机的状态切换成有钱的状态
  25. $this->_juiceMachine->setState($this->_juiceMachine->getHasmoneyState());
  26. }
  27. /* (non-PHPdoc)
  28. * @see State::retreatCoin()
  29. */
  30. public function retreatCoin()
  31. {
  32. // TODO Auto-generated method stub
  33. echo "you have'nt inserted a coin yet<br />";
  34. }
  35. /* (non-PHPdoc)
  36. * @see State::clickButton()
  37. */
  38. public function clickButton()
  39. {
  40. // TODO Auto-generated method stub
  41. echo "you clicked,but you hav'nt inserted a coin yet<br />";
  42. }
  43. /* (non-PHPdoc)
  44. * @see State::dispend()
  45. */
  46. public function dispend()
  47. {
  48. // TODO Auto-generated method stub
  49. echo "you need to pay first<br />";
  50. }
  51. }

HasmoneyState.php

  1. <?php
  2. require_once 'State.php';
  3. class HasmoneyState implements State
  4. {
  5. /**
  6. * 饮料机的实例
  7. *
  8. * @var object
  9. */
  10. private $_juiceMachine;
  11. /**
  12. * 构造方法，主要用于初始化饮料机实例
  13. */
  14. public function __construct($juiceMachine)
  15. {
  16. $this->_juiceMachine = $juiceMachine;
  17. }
  18. /*
  19. * (non-PHPdoc) @see State::insertCoin()
  20. */
  21. public function insertCoin()
  22. {
  23. // TODO Auto-generated method stub
  24. echo "you can't insert another coin!<br />";
  25. }
  26. /*
  27. * (non-PHPdoc) @see State::retreatCoin()
  28. */
  29. public function retreatCoin()
  30. {
  31. // TODO Auto-generated method stub
  32. echo "coin return!<br />";
  33. $this->_juiceMachine->setState($this->_juiceMachine->getNomoneyState());
  34. }
  35. /*
  36. * (non-PHPdoc) @see State::clickButton()
  37. */
  38. public function clickButton()
  39. {
  40. // TODO Auto-generated method stub
  41. echo "you clicked, we are giving you a bottle of juice...<br />";
  42. // 改变饮料机的状态为售出模式
  43. $rand = mt_rand(0, 0);
  44. // 当随机数为0（即1/10的概率）并且饮料机中还有1瓶以上的饮料时
  45. if ($rand == 0 && $this->_juiceMachine->getCount() > 1) {
  46. $this->_juiceMachine->setState($this->_juiceMachine->getWinnerState());
  47. } else {
  48. $this->_juiceMachine->setState($this->_juiceMachine->getSoldState());
  49. }
  50. }
  51. /*
  52. * (non-PHPdoc) @see State::dispend()
  53. */
  54. public function dispend()
  55. {
  56. // TODO Auto-generated method stub
  57. echo "please click the button first<br />";
  58. }
  59. }

SoldoutState.php

  1. <?php
  2. require_once 'State.php';
  3. class SoldoutState implements State{
  4. /**
  5. * 饮料机的实例
  6. *
  7. * @var object
  8. */
  9. private $_juiceMachine;
  10. /**
  11. * 构造方法，主要用于初始化饮料机实例
  12. *
  13. */
  14. public function __construct($juiceMachine){
  15. $this->_juiceMachine = $juiceMachine;
  16. }
  17. /* (non-PHPdoc)
  18. * @see State::insertCoin()
  19. */
  20. public function insertCoin()
  21. {
  22. // TODO Auto-generated method stub
  23. echo "you can't insert coin, the machine is already soldout<br />";
  24. }
  25. /* (non-PHPdoc)
  26. * @see State::retreatCoin()
  27. */
  28. public function retreatCoin()
  29. {
  30. // TODO Auto-generated method stub
  31. echo "you have'nt inserted a coin yet<br />";
  32. }
  33. /* (non-PHPdoc)
  34. * @see State::clickButton()
  35. */
  36. public function clickButton()
  37. {
  38. // TODO Auto-generated method stub
  39. echo "you clicked, but the machine is already soldout<br />";
  40. }
  41. /* (non-PHPdoc)
  42. * @see State::dispend()
  43. */
  44. public function dispend()
  45. {
  46. // TODO Auto-generated method stub
  47. echo "opps, it appears that we don't have any juice left<br />";
  48. }
  49. }

SoldState.php

  1. <?php
  2. require_once 'State.php';
  3. class SoldState implements State{
  4. /**
  5. * 饮料机的实例
  6. *
  7. * @var object
  8. */
  9. private $_juiceMachine;
  10. /**
  11. * 构造方法，主要用于初始化饮料机实例
  12. *
  13. */
  14. public function __construct($juiceMachine){
  15. $this->_juiceMachine = $juiceMachine;
  16. }
  17. /* (non-PHPdoc)
  18. * @see State::insertCoin()
  19. */
  20. public function insertCoin()
  21. {
  22. // TODO Auto-generated method stub
  23. echo "wait a minute, we are giving you a bottle of juice<br />";
  24. }
  25. /* (non-PHPdoc)
  26. * @see State::retreatCoin()
  27. */
  28. public function retreatCoin()
  29. {
  30. // TODO Auto-generated method stub
  31. echo "sorry, you already clicked the botton<br />";
  32. }
  33. /* (non-PHPdoc)
  34. * @see State::clickButton()
  35. */
  36. public function clickButton()
  37. {
  38. // TODO Auto-generated method stub
  39. echo "click twice does'nt get you two bottle of juice<br />";
  40. }
  41. /* (non-PHPdoc)
  42. * @see State::dispend()
  43. */
  44. public function dispend()
  45. {
  46. $this->_juiceMachine->decJuice();
  47. if($this->_juiceMachine->getCount() <= 0){
  48. echo "opps, runing out of juice<br />";
  49. //如果这时饮料机中没有饮料了，将饮料机的状态重置为销售一空
  50. $this->_juiceMachine->setState($this->_juiceMachine->getSoldoutState());
  51. }else{
  52. //将饮料机的状态重置为没有钱
  53. $this->_juiceMachine->setState($this->_juiceMachine->getNomoneyState());
  54. }
  55. }
  56. }

WinnerState.php

  1. <?php
  2. require_once 'State.php';
  3. class WinnerState implements State
  4. {
  5. /**
  6. * 饮料机的实例
  7. *
  8. * @var object
  9. */
  10. private $_juiceMachine;
  11. /**
  12. * 构造方法，主要用于初始化饮料机实例
  13. */
  14. public function __construct($juiceMachine)
  15. {
  16. $this->_juiceMachine = $juiceMachine;
  17. }
  18. /*
  19. * (non-PHPdoc) @see State::insertCoin()
  20. */
  21. public function insertCoin()
  22. {
  23. // TODO Auto-generated method stub
  24. echo "wait a minute, we are giving you a bottle of juice<br />";
  25. }
  26. /*
  27. * (non-PHPdoc) @see State::retreatCoin()
  28. */
  29. public function retreatCoin()
  30. {
  31. // TODO Auto-generated method stub
  32. echo "sorry, you already clicked the botton<br />";
  33. }
  34. /*
  35. * (non-PHPdoc) @see State::clickButton()
  36. */
  37. public function clickButton()
  38. {
  39. // TODO Auto-generated method stub
  40. echo "click twice does'nt get you two bottle of juice<br />";
  41. }
  42. /*
  43. * (non-PHPdoc) @see State::dispend()
  44. */
  45. public function dispend()
  46. {
  47. echo "you are a winner! you get two bottle of juice!<br />";
  48. $this->_juiceMachine->decJuice();
  49. if ($this->_juiceMachine->getCount() > 0) {
  50. $this->_juiceMachine->decJuice();
  51. if ($this->_juiceMachine->getCount() <= 0) {
  52. echo "opps, runing out of juice<br />";
  53. // 如果这时饮料机中没有饮料了，将饮料机的状态重置为销售一空
  54. $this->_juiceMachine->setState($this->_juiceMachine->getSoldoutState());
  55. } else {
  56. // 将饮料机的状态重置为没有钱
  57. $this->_juiceMachine->setState($this->_juiceMachine->getSoldoutState());
  58. }
  59. } else {
  60. echo "opps, runing out of juice<br />";
  61. // 如果这时饮料机中没有饮料了，将饮料机的状态重置为销售一空
  62. $this->_juiceMachine->setState($this->_juiceMachine->getSoldoutState());
  63. }
  64. }
  65. }

JuiceMachine.php

  1. <?php
  2. require_once './state/NomoneyState.php';
  3. require_once './state/HasmoneyState.php';
  4. require_once './state/SoldState.php';
  5. require_once './state/SoldoutState.php';
  6. require_once './state/WinnerState.php';
  7. class JuiceMachine
  8. {
  9. /**
  10. * 记录糖果机当前的状态，初始化状态为售空
  11. *
  12. * @var object
  13. */
  14. private $_state;
  15. /**
  16. * 该变量用于记录饮料机中饮料的数量
  17. */
  18. private $_count;
  19. /**
  20. * 构造方法，最主要是用来初始化count和state属性的
  21. */
  22. public function __construct($count)
  23. {
  24. $this->_state = new SoldoutState($this);
  25. $this->_count = $count;
  26. // 当饮料机中的饮料数量大于零时，将饮料机的状态重置为没有钱的状态。
  27. if ($this->_count > 0) {
  28. $this->_state = new NomoneyState($this);
  29. }
  30. }
  31. /*
  32. * (non-PHPdoc) @see State::insertCoin()
  33. */
  34. public function insertCoin()
  35. {
  36. // TODO Auto-generated method stub
  37. $this->_state->insertCoin();
  38. }
  39. /*
  40. * (non-PHPdoc) @see State::retreatCoin()
  41. */
  42. public function retreatCoin()
  43. {
  44. // TODO Auto-generated method stub
  45. $this->_state->retreatCoin();
  46. }
  47. /*
  48. * (non-PHPdoc) @see State::clickButton()
  49. */
  50. public function clickButton()
  51. {
  52. $this->_state->clickButton();
  53. //其实发放糖果是在用户点击完按钮后机器内部进行的所有没有必要再写一个dispend方法
  54. $this->_state->dispend();
  55. }
  56. /**
  57. * 设置糖果机的状态
  58. *
  59. * @param State $state
  60. */
  61. public function setState(State $state)
  62. {
  63. $this->_state = $state;
  64. }
  65. /**
  66. * 获取没有钱的状态
  67. */
  68. public function getNomoneyState(){
  69. return new NomoneyState($this);
  70. }
  71. /**
  72. * 获取有钱的状态
  73. */
  74. public function getHasmoneyState(){
  75. return new HasmoneyState($this);
  76. }
  77. /**
  78. * 获取售出的状态
  79. */
  80. public function getSoldState(){
  81. return new SoldState($this);
  82. }
  83. /**
  84. * 获取销售一空的状态
  85. */
  86. public function getSoldoutState(){
  87. return new SoldoutState($this);
  88. }
  89. /**
  90. * 获取幸运者的状态
  91. */
  92. public function getWinnerState(){
  93. return new WinnerState($this);
  94. }
  95. /**
  96. * 获取饮料机中饮料的数量
  97. */
  98. public function getCount(){
  99. return $this->_count;
  100. }
  101. /**
  102. * 将饮料数量减一
  103. */
  104. public function decJuice(){
  105. echo "now you get you juice<br />";
  106. //饮料机中的饮料数量减一
  107. $this->_count--;
  108. }
  109. }

index.php

  1. <?php
  2. require_once 'JuiceMachine.php';
  3. $juiceMachine = new JuiceMachine(2);
  4. $juiceMachine->insertCoin();
  5. $juiceMachine->clickButton();
赞 (1)
上一篇4-9
下一篇 12-12

相关推荐

  • PHP设计模式介绍Ⅳ单件模式

    PHP设计模式介绍Ⅳ单件模式几乎所有面向对象的程序中，总有一两个资源被创建出来，在程序应用中持续被共享使用。例如，这样的一个资源，在一个电子商务程序的数据库连接中使用：这个连接在应用程序启动时初始化，程序于是可以有效的执行;当程序结束时，这…
    •php分页
    2015-07-0219464

  • php设计模式之命令模式使用示例

    php设计模式之命令模式使用示例这篇文章主要介绍了php设计模式之命令模式使用示例,命令模式将一个请求封装为一个对象，从而你可用不同的请求对客户进行参数化；对请求排队或记录请求日志，以及支持可撤销操作命令类：1.命令角色：声明了一个给所有具…
    •php图像处理
    2015-07-275170

  • php设计模式之命令模式的应用详解

    php设计模式之命令模式的应用详解命令模式：将一个请求封装为一个对象，从而你可用不同的请求对客户进行参数化；对请求排队或记录请求日志，以及支持可撤销操作。命令类：1.命令角色：声明了一个给所有具体命令类的抽象接口。这是一个抽象角色。2.具体…
    •php上传下载
    2016-03-0513084

  • php设计模式之观察者模式的应用详解

    php设计模式之观察者模式的应用详解观察者模式：定义对象间一种一对多的依赖关系，当一个对象的状态发生改变时，所有依赖于它的对象都得到通知并自动更新。观察者类：1.抽象主题角色：主题角色将所有对观察者对象的引用保存在一个集合中，每个主题可以任…
    •php会话
    2016-08-1717261

  • php设计模式之单例模式使用示例

    php设计模式之单例模式使用示例单例模式也就是只能实例化一次，也就代表在实例化时不可能使用new关键字,下面是使用示例，大家参考使用吧以下为单例模式代码：代码如下:<?phpclassEasyFramework_Easy_Mysql{…
    •php日期
    2018-05-0911990

  • php设计模式之单例模式用法经典示例分析

    这篇文章主要介绍了php设计模式之单例模式用法,结合具体实例形式分析了php单例模式的概念、原理、定义及使用方法,需要的朋友可以参考下。本文实例讲述了php设计模式之单例模式用法，分享给大家供大家参考，具体如下：<?php/***@desc单例模式*目的：防止过多的new对象和clone对象，没有对象的时候new对象并缓存，始终保持都是同一个对象实例*特点：php的单例是进程中的单例，而不像…
    •php应用
    2023-06-05366

  • PHP设计模式之PHP迭代器模式讲解

    今天小编就为大家分享一篇关于PHP设计模式之PHP迭代器模式讲解，小编觉得内容挺不错的，现在分享给大家，具有很好的参考价值，需要的朋友一起跟随小编来看看吧。迭代器有时又称光标（cursor）是程式设计的软件设计模式，可在容器物件（container，例如list或vector）上遍访的接口，设计人员无需关心容器物件的内容。各种语言实作Iterator的方式皆不尽同，有些面向对象语言像Java,C#…
    •php应用
    2023-06-06369

  • PHP面向接口编程,耦合设计模式

    关于接口的理解,接口从更深层次的理解,应是定义,规范,约束,与实现,名实分离的原则,的分离,我们在一般实现一个系统的时候,通常是将定义与实现合为一体,不加分离的,我认为最为理解的系统设计规范应是所有的定义与实现分离,尽管这可能对系统中的某些情况有点繁烦.接口的本身反映了系统设计人员对系统的抽象理解,接口应有两类:第一类是对一个体的抽象,它可对应为一个抽象体(abstractclass)；第二类是对…
    •php面向对象
    2023-06-09439