php封装一个接口类

1. <?php
   Class Response
   {
   //返回数据  
       public static function show($code,$message='',$data='',$type = 'json',$callback='')
       {
           if($type=='json')
           {
               echo     self::jsonEncode($code,$message,$data);
           }elseif($type == 'xml')
           {
               echo     self::xmlEncode($code,$message,$data);
           }elseif($type == 'jsonp')
           {
               echo    $callback.'('.self::jsonEncode($code,$message,$data).')';
           }
   
       }
   
   //json接口  
       public static function jsonEncode($code,$message='',$data='')
       {
           if(!is_numeric($code))
           {
               return '';
           }
   
           $result = array(
               'code' => $code,
               'message' => $message,
               'data' => $data,
           );
           header("Content-type:text/json;chaset=utf-8");
           return json_encode($result);
       }
   //xml接口  
       public static function xmlEncode($code,$message,$data=array())
       {
           if(!is_numeric($code))
           {
               return '';
           }
   
           $result = array(
               'code' => $code,
               'message' => $message,
               'data' => $data,
           );
   
           header("Content-type:text/xml;chaset=utf-8");
           $xml = "<?xml version='1.0' encoding='utf-8'  ?>\n";
           $xml .= "<root>\n";
           $xml .= self::xmlToEncode($result);
           $xml .=    "</root>\n";
   
           return $xml;
   
       }
   
       //xml内容循环  
       public static function xmlToEncode($data)
       {
           if(empty($data))
           {
               return '';
           }
           $xml = $attr = '';
           foreach ($data as $key => $value)
           {
               if(is_numeric($key))
               {
                   $attr = "id='{$key}'";
                   $key = "item";
               }
               $xml .= "<{$key} {$attr}>";
               $xml .= is_array($value) ? self::xmlToEncode($value) : $value ;
               $xml .= "</{$key}>\n";
           }
   
           return $xml;
       }
   }
   
   //二维数据  
   $type = isset($_GET['type'])? $_GET['type'] : 'json';
   
   $callback = isset($_GET['callback'])? $_GET['callback'] : '';
   
   $arr = array(
       'id'=>1,
       'name'=>'jia',
       'type'=>array(1,2,3)
   );
   
   Response::show(200,'数据返回成功',$arr,$type,$callback);