原文連結: http://www.cnblogs.com/xp796/p/5347374.html

php以json或者xml 形式返回給app。明白這點就很好說了，就是把資料包裝成json或者xml，返回給APP

定義抽象APP基類：

<?php  
/** 
 * 定義API抽象類 
*/  
abstract class Api {  
  
    const JSON = 'Json';  
    const XML = 'Xml';  
    const ARR = 'Array';  
      
    /** 
    * 定義工廠方法 
    * param string $type 返回資料型別 
    */  
    public static function factory($type = self::JSON) {  
        $type = isset($_GET['format']) ? $_GET['format'] : $type;  
        $resultClass = ucwords($type);  
        require_once('./Response/' . $type . '.php');  
        return new $resultClass();  
    }  
  
    abstract function response($code, $message, $data);  
}  
 

以xml形式返回給APP：

<?php  
class Xml extends Api {  
    public function response($code, $message = '', $data = array()) {  
        if(!is_numeric($code)) {  
            return '';  
        }  
  
        $result = array(  
            'code' => $code,  
            'message' => $message,  
            'data' => $data  
        );  
  
        header('Content-Type:text/xml');  
        $xml = "<?xml version='1.0' encoding='UTF-8'?>\n";  
        $xml .= "<root>";  
        $xml .= self::xmlToEncode($result);  
        $xml .= "</root>";  
        echo $xml;  
    }  
  
    public static  function xmlToEncode($result) {  
        $xml = $attr = '';  
        foreach($result as $key => $value) {  
                    //判斷鍵值對，如果是數字鍵值不允許  
            if(is_numeric($key)) {  
                $attr = " id='" . $key . "'";  
                $key = "item";  
            }  
            $xml .= "<{$key}{$attr}>";  
                        //以遞迴形式返回，主要是因為陣列在xml中顯示是array，必須顯示出來具體鍵值對  
            $xml .= is_array($value) ? self::xmlToEncode($value) : $value;  
            $xml .= "</{$key}>\n";  
        }  
        return $xml;  
    }  
}  
 

<?php  
/** 
 * 按xml方式輸出通訊資料 
*/  
class Json extends Api {  
    public function response($code, $message = '', $data = array()) {  
        if(!(is_numeric($code))) {  
            return '';  
        }  
  
        $result = array(  
            'code' => $code,  
            'message' => $message,  
            'data' => $data  
        );  
  
        echo json_encode($result);  
        exit;  
    }  
}  
 

<?php  
  
class Response {  
    const JSON = "json";  
    /** 
    * 按綜合方式輸出通訊資料 
    * @param integer $code 狀態碼 
    * @param string $message 提示資訊 
    * @param array $data 資料 
    * @param string $type 資料型別 
    * return string 
    */  
    public static function show($code, $message = '', $data = array(), $type = self::JSON) {  
        if(!is_numeric($code)) {  
            return '';  
        }  
  
        $type = isset($_GET['format']) ? $_GET['format'] : self::JSON;  
  
        $result = array(  
            'code' => $code,  
            'message' => $message,  
            'data' => $data,  
        );  
  
        if($type == 'json') {  
            self::json($code, $message, $data);  
            exit;  
        } elseif($type == 'array') { //適合除錯程式碼  
            var_dump($result);  
        } elseif($type == 'xml') {  
            self::xmlEncode($code, $message, $data);  
            exit;  
        } else {  
            // TODO  
        }  
    }  
    /** 
    * 按json方式輸出通訊資料 
    * @param integer $code 狀態碼 
    * @param string $message 提示資訊 
    * @param array $data 資料 
    * return string 
    */  
    public static function json($code, $message = '', $data = array()) {  
          
        if(!is_numeric($code)) {  
            return '';  
        }  
  
        $result = array(  
            'code' => $code,  
            'message' => $message,  
            'data' => $data  
        );  
  
        echo json_encode($result);  
        exit;  
    }  
  
    /** 
    * 按xml方式輸出通訊資料 
    * @param integer $code 狀態碼 
    * @param string $message 提示資訊 
    * @param array $data 資料 
    * return string 
    */  
    public static function xmlEncode($code, $message, $data = array()) {  
        if(!is_numeric($code)) {  
            return '';  
        }  
  
        $result = array(  
            'code' => $code,  
            'message' => $message,  
            'data' => $data,  
        );  
  
        header("Content-Type:text/xml");  
        $xml = "<?xml version='1.0' encoding='UTF-8'?>\n";  
        $xml .= "<root>\n";  
  
        $xml .= self::xmlToEncode($result);  
  
        $xml .= "</root>";  
        echo $xml;  
    }  
  
    public static function xmlToEncode($data) {  
  
        $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;  
    }  
  
}