详解PHP中的状态模式编程

 <?php 
  
 / 
   抽象状态类 
   @author wzy 
   
  / 
 interface VoteState 
 { 
  
  / 
    需要实现的公共方法 
   / 
  public function vote (); 
 } 
  
 / 
   具体状态——正常投票 
   
   @author wzy 
     
  / 
 class NormalVoteState implements VoteState 
 { 
  
  public function vote () 
  { 
   echo "这是一个正常投票!"; 
  } 
 } 
  
 / 
   具体状态——恶意投票 
   
   @author wzy 
     
  / 
 class RepeatVoteState implements VoteState 
 { 
  
  public function vote () 
  { 
   echo "这是一个恶意投票!"; 
  } 
 } 
  
 / 
   具体状态——黑名单投票 
   
   @author wzy 
     
  / 
 class BlockVoteState implements VoteState 
 { 
  
  public function vote () 
  { 
   echo "这是一个黑名单投票!"; 
  } 
 } 
  
 / 
   Context角色 
  / 
 class VoteManager 
 { 
  
  / 
    投票数量 
    
    @var int 
   / 
  private $vote_count; 
  
  / 
    状态类实例 
    
    @var object 
   / 
  private $voteInstance; 
  
  / 
    构造函数，初始化成员属性 
    
    @param int $count    
   / 
  public function __construct ($count = 1) 
  { 
   $this->vote_count = $count; 
  } 
  
  / 
    客户端调用的接口函数 
   / 
  public function setState ($count) 
  { 
   if (! is_null($count)) { 
    $this->vote_count = $count; 
   } 
   if ($this->vote_count < 5) { 
    $this->voteInstance = new NormalVoteState(); 
   } else 
    if ($this->vote_count < 8) { 
     $this->voteInstance = new RepeatVoteState(); 
    } else { 
     $this->voteInstance = new BlockVoteState(); 
    } 
    
   $this->voteInstance->vote(); 
  } 
 } 
  
 / 
   模拟客户端操作 
  / 
  
 $object = new VoteManager(); 
 $object->setState(1); 
 echo "<br>"; 
 $object->setState(6); 
 echo "<br>"; 
 $object->setState(10);