PHP配置文件处理类代码

<?php
/* 
* 来源: http://www.xuehuwang.com/ 
* 作者: 雪狐博客 
* 应用: 用于处理配置数据
* 搜集整理：www.jb200.com
**/
    final class Config {  
    private $data = array();  
                
    public function get($key) {  
        return (isset($this->data[$key]) ? $this->data[$key] : NULL);  
    }     
                    
    public function set($key, $value) {  
        $this->data[$key] = $value;  
    }  
                
    public function has($key) {  
        return isset($this->data[$key]);  
    }  
                
    public function load($filename) {  
        $file = DIR_CONFIG . $filename . '.php';  
                        
        if (file_exists($file)) {   
            $cfg = array();  
                      
            require($file);  
                      
            $this->data = array_merge($this->data, $cfg);  
        } else {  
            exit('Error: Could not load config ' . $filename . '!');  
        }  
    }  
}