首页
所有分类
TAGS
文字工具 EMOJI BIBLE
编程 PHP

PHP设计模式入门之状态模式原理与实现方法分析

Posted in PHP onApril 26, 2020

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

<?php
/**
 * 饮料机
 * @author ben
 *
 */
class JuiceMachine{
 /**
 * 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
 * 
 * 没钱的状态
 * @var INT
 */
 const NOMONEY = 0;
 
 /**
 * 有钱的状态
 * @var INT
 */
 const HASMONEY = 1;
 
 /**
 * 成功售出的状态
 * @var INT
 */
 const SOLD = 2;
 
 /**
 * 销售一空的状态
 * @var INT
 */
 const SOLDOUT = 3;
 
 /**
 * 记录糖果机当前的状态，初始化状态为售空
 * @var INT
 */
 private $_state = JuiceMachine::SOLDOUT;
 
 /**
 * 该变量用于记录饮料机中饮料的数量
 */
 private $_count; 
 
 /**
 * 构造方法，最主要是用来初始化count和state属性的
 */
 public function __construct($count){
   $this->_count = $count;
   //当饮料机中的饮料数量大于零时，将饮料机的状态重置为没有钱的状态。
   if($this->_count > 0){
     $this->_state = JuiceMachine::NOMONEY;
   }
 }
 
 /**
 * 投入硬币
 */
 public function insertCoin(){
   if($this->_state == JuiceMachine::HASMONEY ){
     echo "you can't insert another coin!<br />";
   }elseif($this->_state == JuiceMachine::NOMONEY){
     echo "you just insert a coin<br />";
     $this->_state = JuiceMachine::HASMONEY;
   }elseif($this->_state == JuiceMachine::SOLD){
     echo "wait a minute, we are giving you a bottle of juice<br />";
   }elseif($this->_state == JuiceMachine::SOLDOUT){
     echo "you can't insert coin, the machine is already soldout<br />";
   }
 }
 
 /**
 * 退回硬币
 */
 public function retreatCoin(){
   if($this->_state == JuiceMachine::HASMONEY ){
     echo "coin return!<br />";
     $this->_state = JuiceMachine::NOMONEY;
   }elseif($this->_state == JuiceMachine::NOMONEY){
     echo "you have'nt inserted a coin yet<br />";
   }elseif($this->_state == JuiceMachine::SOLD){
     echo "sorry, you already clicked the botton<br />";
   }elseif($this->_state == JuiceMachine::SOLDOUT){
     echo "you have'nt inserted a coin yet<br />";
   }
 }
 
 /**
 * 点击饮料对应的按钮
 */
 public function clickButton(){
   if($this->_state == JuiceMachine::HASMONEY ){
     echo "you clicked, we are giving you a bottle of juice...<br />";
     $this->_state = JuiceMachine::SOLD;  //改变饮料机的状态为售出模式
     $this->dispend();
   }elseif($this->_state == JuiceMachine::NOMONEY){
     echo "you clicked,but you hav'nt inserted a coin yet<br />";
   }elseif($this->_state == JuiceMachine::SOLD){
     echo "click twice does'nt get you two bottle of juice<br />";
   }elseif($this->_state == JuiceMachine::SOLDOUT){
     echo "you clicked, but the machine is already soldout<br />";
   }
 }
 
 /**
 * 发放饮料
 */
 public function dispend(){
   if($this->_state == JuiceMachine::HASMONEY ){
     echo "please click the button first<br />";
   }elseif($this->_state == JuiceMachine::NOMONEY){
     echo "you need to pay first<br />";
   }elseif($this->_state == JuiceMachine::SOLD){
     echo "now you get you juice<br />";
     //饮料机中的饮料数量减一
     $this->_count--;
     if($this->_count <= 0){
       echo "opps, runing out of juice<br />";
       //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
       $this->_state = JuiceMachine::SOLDOUT;
     }else{
       //将饮料机的状态重置为没有钱
       $this->_state = JuiceMachine::NOMONEY;
     }
   }elseif($this->_state == JuiceMachine::SOLDOUT){
     //其实这种情况不应该出现
     echo "opps, it appears that we don't have any juice left<br />";
   }
 }
}

index.php

<?php
require_once 'JuiceMachine.php';
 
$juiceMachine = new JuiceMachine(1);
 
$juiceMachine->insertCoin();
$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：

PHP设计模式入门之状态模式原理与实现方法分析

在我们这个项目中的实际类图如下：

PHP设计模式入门之状态模式原理与实现方法分析

具体实现代码：

State.php

<?php
interface State{
  
  /**
   * 插入硬币
   */
  public function insertCoin();
  
  /**
   * 回退硬币
   */
  public function retreatCoin();
  
  /**
   * 点击按钮
   */
  public function clickButton();
  
  /**
   * 发放饮料
   */
  public function dispend();
}

NomoneyState.php

<?php
require_once 'State.php';
class NomoneyState implements State{
  
  /**
   * 饮料机的实例
   * 
   * @var object
   */
  private $_juiceMachine;
  
  /**
   * 构造方法，主要用于初始化饮料机实例
   * 
   */
  public function __construct($juiceMachine){
    $this->_juiceMachine = $juiceMachine;
  }
  
 /* (non-PHPdoc)
   * @see State::insertCoin()
   */
  public function insertCoin()
  {
    // TODO Auto-generated method stub
    echo "you just insert a coin<br />";
    //将饮料机的状态切换成有钱的状态
    $this->_juiceMachine->setState($this->_juiceMachine->getHasmoneyState());
  }
 
 /* (non-PHPdoc)
   * @see State::retreatCoin()
   */
  public function retreatCoin()
  {
    // TODO Auto-generated method stub
    echo "you have'nt inserted a coin yet<br />";
  }
 
 /* (non-PHPdoc)
   * @see State::clickButton()
   */
  public function clickButton()
  {
    // TODO Auto-generated method stub
    echo "you clicked,but you hav'nt inserted a coin yet<br />";
  }
 
 /* (non-PHPdoc)
   * @see State::dispend()
   */
  public function dispend()
  {
    // TODO Auto-generated method stub
    echo "you need to pay first<br />";
  }
}

HasmoneyState.php

<?php
require_once 'State.php';
 
class HasmoneyState implements State
{
 
  /**
   * 饮料机的实例
   *
   * @var object
   */
  private $_juiceMachine;
 
  /**
   * 构造方法，主要用于初始化饮料机实例
   */
  public function __construct($juiceMachine)
  {
    $this->_juiceMachine = $juiceMachine;
  }
  
  /*
   * (non-PHPdoc) @see State::insertCoin()
   */
  public function insertCoin()
  {
    // TODO Auto-generated method stub
    echo "you can't insert another coin!<br />";
  }
  
  /*
   * (non-PHPdoc) @see State::retreatCoin()
   */
  public function retreatCoin()
  {
    // TODO Auto-generated method stub
    echo "coin return!<br />";
    $this->_juiceMachine->setState($this->_juiceMachine->getNomoneyState());
  }
  
  /*
   * (non-PHPdoc) @see State::clickButton()
   */
  public function clickButton()
  {
    // TODO Auto-generated method stub
    echo "you clicked, we are giving you a bottle of juice...<br />";
    // 改变饮料机的状态为售出模式
    $rand = mt_rand(0, 0);
    // 当随机数为0（即1/10的概率）并且饮料机中还有1瓶以上的饮料时
    if ($rand == 0 && $this->_juiceMachine->getCount() > 1) {
      $this->_juiceMachine->setState($this->_juiceMachine->getWinnerState());
    } else {
      $this->_juiceMachine->setState($this->_juiceMachine->getSoldState());
    }
  }
  
  /*
   * (non-PHPdoc) @see State::dispend()
   */
  public function dispend()
  {
    // TODO Auto-generated method stub
    echo "please click the button first<br />";
  }
}

SoldoutState.php

<?php
require_once 'State.php';
class SoldoutState implements State{
  
  /**
   * 饮料机的实例
   *
   * @var object
   */
  private $_juiceMachine;
  
  /**
   * 构造方法，主要用于初始化饮料机实例
   *
   */
  public function __construct($juiceMachine){
    $this->_juiceMachine = $juiceMachine;
  }
  
 /* (non-PHPdoc)
   * @see State::insertCoin()
   */
  public function insertCoin()
  {
    // TODO Auto-generated method stub
    echo "you can't insert coin, the machine is already soldout<br />";
  }
 
 /* (non-PHPdoc)
   * @see State::retreatCoin()
   */
  public function retreatCoin()
  {
    // TODO Auto-generated method stub
    echo "you have'nt inserted a coin yet<br />";
  }
 
 /* (non-PHPdoc)
   * @see State::clickButton()
   */
  public function clickButton()
  {
    // TODO Auto-generated method stub
    echo "you clicked, but the machine is already soldout<br />";
  }
 
 /* (non-PHPdoc)
   * @see State::dispend()
   */
  public function dispend()
  {
    // TODO Auto-generated method stub
    echo "opps, it appears that we don't have any juice left<br />";
  }
}

SoldState.php

<?php
require_once 'State.php';
class SoldState implements State{
  
  /**
   * 饮料机的实例
   *
   * @var object
   */
  private $_juiceMachine;
  
  /**
   * 构造方法，主要用于初始化饮料机实例
   *
   */
  public function __construct($juiceMachine){
    $this->_juiceMachine = $juiceMachine;
  }
  
 /* (non-PHPdoc)
   * @see State::insertCoin()
   */
  public function insertCoin()
  {
    // TODO Auto-generated method stub
    echo "wait a minute, we are giving you a bottle of juice<br />";
  }
 
 /* (non-PHPdoc)
   * @see State::retreatCoin()
   */
  public function retreatCoin()
  {
    // TODO Auto-generated method stub
    echo "sorry, you already clicked the botton<br />";
  }
 
 /* (non-PHPdoc)
   * @see State::clickButton()
   */
  public function clickButton()
  {
    // TODO Auto-generated method stub
    echo "click twice does'nt get you two bottle of juice<br />";
  }
 
 /* (non-PHPdoc)
   * @see State::dispend()
   */
  public function dispend()
  {
    $this->_juiceMachine->decJuice();
    if($this->_juiceMachine->getCount() <= 0){
      echo "opps, runing out of juice<br />";
      //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
       $this->_juiceMachine->setState($this->_juiceMachine->getSoldoutState());
    }else{
      //将饮料机的状态重置为没有钱
       $this->_juiceMachine->setState($this->_juiceMachine->getNomoneyState());
    }
  }
  
}

WinnerState.php

<?php
require_once 'State.php';
 
class WinnerState implements State
{
 
  /**
   * 饮料机的实例
   *
   * @var object
   */
  private $_juiceMachine;
 
  /**
   * 构造方法，主要用于初始化饮料机实例
   */
  public function __construct($juiceMachine)
  {
    $this->_juiceMachine = $juiceMachine;
  }
  
  /*
   * (non-PHPdoc) @see State::insertCoin()
   */
  public function insertCoin()
  {
    // TODO Auto-generated method stub
    echo "wait a minute, we are giving you a bottle of juice<br />";
  }
  
  /*
   * (non-PHPdoc) @see State::retreatCoin()
   */
  public function retreatCoin()
  {
    // TODO Auto-generated method stub
    echo "sorry, you already clicked the botton<br />";
  }
  
  /*
   * (non-PHPdoc) @see State::clickButton()
   */
  public function clickButton()
  {
    // TODO Auto-generated method stub
    echo "click twice does'nt get you two bottle of juice<br />";
  }
  
  /*
   * (non-PHPdoc) @see State::dispend()
   */
  public function dispend()
  {
    echo "you are a winner! you get two bottle of juice!<br />";
    $this->_juiceMachine->decJuice();
    if ($this->_juiceMachine->getCount() > 0) {
      $this->_juiceMachine->decJuice();
      if ($this->_juiceMachine->getCount() <= 0) {
        echo "opps, runing out of juice<br />";
        // 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
        $this->_juiceMachine->setState($this->_juiceMachine->getSoldoutState());
      } else {
        // 将饮料机的状态重置为没有钱
        $this->_juiceMachine->setState($this->_juiceMachine->getSoldoutState());
      }
    } else {
      echo "opps, runing out of juice<br />";
      // 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
      $this->_juiceMachine->setState($this->_juiceMachine->getSoldoutState());
    }
  }
}

JuiceMachine.php

<?php
require_once './state/NomoneyState.php';
require_once './state/HasmoneyState.php';
require_once './state/SoldState.php';
require_once './state/SoldoutState.php';
require_once './state/WinnerState.php';
 
class JuiceMachine
{
 
  /**
   * 记录糖果机当前的状态，初始化状态为售空
   * 
   * @var object
   */
  private $_state;
 
  /**
   * 该变量用于记录饮料机中饮料的数量
   */
  private $_count;
 
  /**
   * 构造方法，最主要是用来初始化count和state属性的
   */
  public function __construct($count)
  {
    $this->_state = new SoldoutState($this);
    $this->_count = $count;
    // 当饮料机中的饮料数量大于零时，将饮料机的状态重置为没有钱的状态。
    if ($this->_count > 0) {
      $this->_state = new NomoneyState($this);
    }
  }
  
  /*
   * (non-PHPdoc) @see State::insertCoin()
   */
  public function insertCoin()
  {
    // TODO Auto-generated method stub
    $this->_state->insertCoin();
  }
  
  /*
   * (non-PHPdoc) @see State::retreatCoin()
   */
  public function retreatCoin()
  {
    // TODO Auto-generated method stub
    $this->_state->retreatCoin();
  }
  
  /*
   * (non-PHPdoc) @see State::clickButton()
   */
  public function clickButton()
  {
    $this->_state->clickButton();
    //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
    $this->_state->dispend();
  }
  
  /**
   * 设置糖果机的状态
   * 
   * @param State $state
   */
  public function setState(State $state)
  {
    $this->_state = $state;
  }
  
  /**
   * 获取没有钱的状态
   */
  public function getNomoneyState(){
    return new NomoneyState($this);
  }
  
  /**
   * 获取有钱的状态
   */
  public function getHasmoneyState(){
    return new HasmoneyState($this);
  }
  
  /**
   * 获取售出的状态
   */
  public function getSoldState(){
    return new SoldState($this);
  }
  
  /**
   * 获取销售一空的状态
   */
  public function getSoldoutState(){
    return new SoldoutState($this);
  }
  
  /**
   * 获取幸运者的状态
   */
  public function getWinnerState(){
    return new WinnerState($this);
  }
  
  /**
   * 获取饮料机中饮料的数量
   */
  public function getCount(){
    return $this->_count;
  }
  
  /**
   * 将饮料数量减一
   */
  public function decJuice(){
    echo "now you get you juice<br />";
    //饮料机中的饮料数量减一
    $this->_count--;
  }
  
}

index.php

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

希望本文所述对大家PHP程序设计有所帮助。

PHP设计模式入门之状态模式原理与实现方法分析

- Author -

dongxie548

声明：登载此文出于传递更多信息之目的，并不意味着赞同其观点或证实其描述。

PHP 相关文章推荐
ajax php传递和接收变量实现思路及代码
Dec 19 PHP
关于PHP自动判断字符集并转码的详解
Jun 26 PHP
PHP实现AES256加密算法实例
Sep 22 PHP
php实现webservice实例
Nov 06 PHP
学习php设计模式 php实现备忘录模式(Memento)
Dec 09 PHP
php 无限级分类 获取顶级分类ID
Mar 13 PHP
老司机传授Ubuntu下Apache+PHP+MySQL环境搭建攻略
Mar 20 PHP
php 生成签名及验证签名详解
Oct 26 PHP
php使用正则表达式去掉html中的注释方法
Nov 03 PHP
浅谈PHP的exec()函数无返回值排查方法(必看)
Mar 31 PHP
PHP实现网站访问量计数器
Oct 27 PHP
PHP中递归的实现实例详解
Nov 14 PHP
PHP设计模式入门之迭代器模式原理与实现方法分析
Apr 26 #PHP
PHP中迭代器的简单实现及Yii框架中的迭代器实现方法示例
Apr 26 #PHP
PHP设计模式之迭代器模式Iterator实例分析【对象行为型】
Apr 26 #PHP
Yii Framework框架开发微信公众平台示例
Apr 26 #PHP
PHP随机生成中文段落示例【测试网站内容时使用】
Apr 26 #PHP
PHP过滤器 filter_has_var() 函数用法实例分析
Apr 23 #PHP
PHP优化之批量操作MySQL实例分析
Apr 23 #PHP
Bean(3) 自动化(1) 数据类型(8) metaclass(1) IOC(3) XML(1) 触发器(3) Geospatial(1) zip(1) enumerate(1)
You might like
PHP与javascript的两种交互方式
2006/10/09 PHP
PHP5 的对象赋值机制介绍
2011/08/02 PHP
Yii使用find findAll查找出指定字段的实现方法
2014/09/05 PHP
Yii2分页的使用及其扩展方法详解
2016/05/23 PHP
Laravel框架路由和控制器的绑定操作方法
2018/06/12 PHP
Javascript调试工具（下载）
2007/01/09 Javascript
TextArea 控件的最大长度问题(js json)
2009/12/16 Javascript
事件绑定之小测试  onclick &amp;&amp; addEventListener
2011/07/31 Javascript
尝试在让script的type属性等于text/html
2013/01/15 Javascript
javascript DIV实现跟随鼠标移动
2020/03/19 Javascript
JS实现环形进度条（从0到100%）效果
2016/07/05 Javascript
Node.js服务器开启Gzip压缩教程
2017/08/11 Javascript
Javascript中JSON数据分组优化实践及JS操作JSON总结
2017/12/22 Javascript
微信小程序实现发红包功能
2018/07/11 Javascript
element el-input directive数字进行控制
2018/10/11 Javascript
监控Nodejs的性能实例代码
2019/07/02 NodeJs
解决微信小程序中的滚动穿透问题
2019/09/16 Javascript
使用nodeJS中的fs模块对文件及目录进行读写,删除,追加,等操作详解
2020/02/06 NodeJs
vue cli4下环境变量和模式示例详解
2020/04/09 Javascript
python读写ini文件示例(python读写文件)
2014/03/25 Python
Python中使用动态变量名的方法
2014/05/06 Python
详解Python中heapq模块的用法
2016/06/28 Python
Python实现破解猜数游戏算法示例
2017/09/25 Python
python使用opencv按一定间隔截取视频帧
2018/03/06 Python
Python实现的寻找前5个默尼森数算法示例
2018/03/25 Python
对python PLT中的image和skimage处理图片方法详解
2019/01/10 Python
opencv与numpy的图像基本操作
2019/03/08 Python
用python打印菱形的实操方法和代码
2019/06/25 Python
python 使用pygame工具包实现贪吃蛇游戏(多彩版)
2019/10/30 Python
opencv3/C++ 平面对象识别&amp;透视变换方式
2019/12/11 Python
施华洛世奇水晶荷兰官方网站：SWAROVSKI荷兰
2017/05/12 全球购物
PHP经典面试题
2016/09/03 面试题
普通党员四风问题对照检查材料
2014/09/27 职场文书
暑假社会实践证明格式
2014/10/28 职场文书
学生会任命书范本
2015/09/21 职场文书
Golang 并发下的问题定位及解决方案
2022/03/16 Golang