PHP 单列模式实例讲解以及参考网址

1,http://blog.csdn.net/jungsagacity/article/details/7618587

2,http://www.cnblogs.com/lh460795/archive/2013/07/30/3225650.html

实例应用

Myclass.php

<?php
header("Content-type: text/html; charset=utf-8");
header('Access-Control-Allow-Origin:*'); 
$BiaDuak = '2q5OVS3LlFuZcoXGtXvqxAYq';//定义一般变量
define("accessKeyId","8LdVru54GybHc2DB"); //定义常量
class DbHelp
{
  public  $servername="5657d48145af1.sh.cdb.myqcloud.com:4065";
  public  $username="mydata" ;
  public  $password="w12345";
  public  $dbname="allhelp";
  private static $_instance;
  public static function getInstance()    
  {    
    if(! (self::$_instance instanceof self) )   
    {    
        self::$_instance = new self();    
    }  
    return self::$_instance;    
  }
  private function __construct(){}   
  private function __clone(){}
}
?>

　　other.php

<?php 
header("Content-type: text/html; charset=utf-8");
header('Content-Type: application/json');
header('Access-Control-Allow-Origin:*'); 
require "Myclass.php";
$dbcontext=DbHelp::getInstance(); 
echo $BiaDuak;
echo accessKeyId;
echo $dbcontext->servername;
?>