PHP开发APP接口

php以json或者xml 形式返回给app。明白这点就很好说了，就是把数据包装成json或者xml，返回给APP。

定义抽象APP基类：

<?php
/**
 * 定义API抽象类
*/
abstract class Api {

  const JSON = 'Json';
  const XML = 'Xml';
  const ARR = 'Array';
  
  /**
  * 定义工厂方法
  * param string $type 返回数据类型
  */
  public static function factory($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形式返回给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 => $value) {
                    //判断键值对，如果是数字键值不允许
      if(is_numeric($key)) {
        $attr = " id='" . $key . "'";
        $key = "item";
      }
      $xml .= "<{$key}{$attr}>";
  //以递归形式返回，主要是因为数组在xml中显示是array，必须显示出来具体键值对
      $xml .= is_array($value) ? self::xmlToEncode($value) : $value;
      $xml .= "</{$key}>\n";
    }
    return $xml;
  }
}

以json格式返回数据：

<?php
/**
 * 按xml方式输出通信数据
*/
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;
  }
}

也可以采用这种方式组装返回数据：

<?php

class Response {
  const JSON = "json";
  /**
  * 按综合方式输出通信数据
  * @param integer $code 状态码
  * @param string $message 提示信息
  * @param array $data 数据
  * @param string $type 数据类型
  * return string
  */
  public static function show($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') { //适合调试代码
      var_dump($result);
    } elseif($type == 'xml') {
      self::xmlEncode($code, $message, $data);
      exit;
    } else {
      // TODO
    }
  }
  /**
  * 按json方式输出通信数据
  * @param integer $code 状态码
  * @param string $message 提示信息
  * @param array $data 数据
  * return string
  */
  public static function json($code, $message = '', $data = array()) {
    
    if(!is_numeric($code)) {
      return '';
    }

    $result = array(
      'code' => $code,
      'message' => $message,
      'data' => $data
    );

    echo json_encode($result);
    exit;
  }

  /**
  * 按xml方式输出通信数据
  * @param integer $code 状态码
  * @param string $message 提示信息
  * @param array $data 数据
  * return string
  */
  public static function xmlEncode($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;
  }

}

实例

<?php
// http://app.com/list.php?page-=1&pagesize=12
require_once('./response.php');
require_once('./file.php');

$file = new File();
$data = $file->cacheData('index_cron_cahce');
if($data) {
    return Response::show(200, '首页数据获取成功', $data);
}else{
    return Response::show(400, '首页数据获取失败', $data);
}
exit;
require_once('./db.php');
require_once('./file.php');
$page = isset($_GET['page']) ? $_GET['page'] : 1;
$pageSize = isset($_GET['pagesize']) ? $_GET['pagesize'] : 6;
if(!is_numeric($page) || !is_numeric($pageSize)) {
    return Response::show(401, '数据不合法');
}

$offset = ($page - 1) * $pageSize;

$sql = "select * from video where status = 1 order by orderby desc limit ". $offset ." , ".$pageSize;
$cache = new File();
$videos = array();
if(!$videos = $cache->cacheData('index_mk_cache' . $page .'-' . $pageSize)) {
    echo 1;exit;
    try {
        $connect = Db::getInstance()->connect();
    } catch(Exception $e) {
        // $e->getMessage();
        return Response::show(403, '数据库链接失败');
    }
    $result = mysql_query($sql, $connect); 
    
    while($video = mysql_fetch_assoc($result)) {
        $videos[] = $video;
    }

    if($videos) {
        $cache->cacheData('index_mk_cache' . $page .'-' . $pageSize, $videos, 1200);
    }
}

if($videos) {
    return Response::show(200, '首页数据获取成功', $videos);
} else {
    return Response::show(400, '首页数据获取失败', $videos);
}