我有我正在开发的这个 ajax Web 应用程序，它基本上使用 ajax 调用 google moderator api 并返回结果以对它们做一些事情。我知道 AJAX 本身不能发出跨域请求，所以我还使用 cURL 放置了一个基于 Web 服务器的 php 代理来接收 URL、发出请求并发回数据。我遇到的问题是，无论我做什么，我发出的每个请求都以 0 的 Http 状态代码返回。我不完全确定 0 代码的真正含义，但我认为它与失败的连接有关. 这是我的一些代码：
function populate() {
var number = parseInt('93683',16);
var url='https://www.googleapis.com/moderator/v1/series/'+number+'?key='+superkey;
var xhttp = null;
xhttp = new XMLHttpRequest();
xhttp.onreadystatechange=function() {
if (xhttp.readyState==4 && xhttp.status==200) {
data = xhttp.responseText;
data = data.slice(data.indexOf('{'));
data = jQuery.parseJSON(data);
alert(data.contents);
}
else {
alert('Error: '+xhttp.status);
}
}
xhttp.open("GET",base_url+url,true);
xhttp.send(null);
}
发生的事情是我发送请求，以下 php 文件获取它并发送请求。
// Script: Simple PHP Proxy: Get external HTML, JSON and more!
//
// *Version: 1.6, Last updated: 1/24/2009*
//
// Project Home - http://benalman.com/projects/php-simple-proxy/
// GitHub - http://github.com/cowboy/php-simple-proxy/
// Source - http://github.com/cowboy/php-simple-proxy/raw/master/ba-simple-proxy.php
//
// About: License
//
// Copyright (c) 2010 "Cowboy" Ben Alman,
// Dual licensed under the MIT and GPL licenses.
// http://benalman.com/about/license/
//
// About: Examples
//
// This working example, complete with fully commented code, illustrates one way
// in which this PHP script can be used.
//
// Simple - http://benalman.com/code/projects/php-simple-proxy/examples/simple/
//
// About: Release History
//
// 1.6 - (1/24/2009) Now defaults to JSON mode, which can now be changed to
// native mode by specifying ?mode=native. Native and JSONP modes are
// disabled by default because of possible XSS vulnerability issues, but
// are configurable in the PHP script along with a url validation regex.
// 1.5 - (12/27/2009) Initial release
//
// Topic: GET Parameters
//
// Certain GET (query string) parameters may be passed into ba-simple-proxy.php
// to control its behavior, this is a list of these parameters.
//
// url - The remote URL resource to fetch. Any GET parameters to be passed
// through to the remote URL resource must be urlencoded in this parameter.
// mode - If mode=native, the response will be sent using the same content
// type and headers that the remote URL resource returned. If omitted, the
// response will be JSON (or JSONP). <Native requests> and <JSONP requests>
// are disabled by default, see <Configuration Options> for more information.
// callback - If specified, the response JSON will be wrapped in this named
// function call. This parameter and <JSONP requests> are disabled by
// default, see <Configuration Options> for more information.
// user_agent - This value will be sent to the remote URL request as the
// `User-Agent:` HTTP request header. If omitted, the browser user agent
// will be passed through.
// send_cookies - If send_cookies=1, all cookies will be forwarded through to
// the remote URL request.
// send_session - If send_session=1 and send_cookies=1, the SID cookie will be
// forwarded through to the remote URL request.
// full_headers - If a JSON request and full_headers=1, the JSON response will
// contain detailed header information.
// full_status - If a JSON request and full_status=1, the JSON response will
// contain detailed cURL status information, otherwise it will just contain
// the `http_code` property.
//
// Topic: POST Parameters
//
// All POST parameters are automatically passed through to the remote URL
// request.
//
// Topic: JSON requests
//
// This request will return the contents of the specified url in JSON format.
//
// Request:
//
// > ba-simple-proxy.php?url=http://example.com/
//
// Response:
//
// > { "contents": "<html>...</html>", "headers": {...}, "status": {...} }
//
// JSON object properties:
//
// contents - (String) The contents of the remote URL resource.
// headers - (Object) A hash of HTTP headers returned by the remote URL
// resource.
// status - (Object) A hash of status codes returned by cURL.
//
// Topic: JSONP requests
//
// This request will return the contents of the specified url in JSONP format
// (but only if $enable_jsonp is enabled in the PHP script).
//
// Request:
//
// > ba-simple-proxy.php?url=http://example.com/&callback=foo
//
// Response:
//
// > foo({ "contents": "<html>...</html>", "headers": {...}, "status": {...} })
//
// JSON object properties:
//
// contents - (String) The contents of the remote URL resource.
// headers - (Object) A hash of HTTP headers returned by the remote URL
// resource.
// status - (Object) A hash of status codes returned by cURL.
//
// Topic: Native requests
//
// This request will return the contents of the specified url in the format it
// was received in, including the same content-type and other headers (but only
// if $enable_native is enabled in the PHP script).
//
// Request:
//
// > ba-simple-proxy.php?url=http://example.com/&mode=native
//
// Response:
//
// > <html>...</html>
//
// Topic: Notes
//
// * Assumes magic_quotes_gpc = Off in php.ini
//
// Topic: Configuration Options
//
// These variables can be manually edited in the PHP file if necessary.
//
// $enable_jsonp - Only enable <JSONP requests> if you really need to. If you
// install this script on the same server as the page you're calling it
// from, plain JSON will work. Defaults to false.
// $enable_native - You can enable <Native requests>, but you should only do
// this if you also whitelist specific URLs using $valid_url_regex, to avoid
// possible XSS vulnerabilities. Defaults to false.
// $valid_url_regex - This regex is matched against the url parameter to
// ensure that it is valid. This setting only needs to be used if either
// $enable_jsonp or $enable_native are enabled. Defaults to '/.*/' which
// validates all URLs.
//
// ############################################################################
// Change these configuration options if needed, see above descriptions for info.
$enable_jsonp = false;
$enable_native = false;
$valid_url_regex = '/.*/';
// ############################################################################
$url = $_GET['url'];
if ( !$url ) {
// Passed url not specified.
$contents = 'ERROR: url not specified';
$status = array( 'http_code' => 'ERROR' );
} else if ( !preg_match( $valid_url_regex, $url ) ) {
// Passed url doesn't match $valid_url_regex.
$contents = 'ERROR: invalid url';
$status = array( 'http_code' => 'ERROR' );
} else {
$ch = curl_init( $url );
if ( strtolower($_SERVER['REQUEST_METHOD']) == 'post' ) {
curl_setopt( $ch, CURLOPT_POST, true );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $_POST );
}
if ( $_GET['send_cookies'] ) {
$cookie = array();
foreach ( $_COOKIE as $key => $value ) {
$cookie[] = $key . '=' . $value;
}
if ( $_GET['send_session'] ) {
$cookie[] = SID;
}
$cookie = implode( '; ', $cookie );
curl_setopt( $ch, CURLOPT_COOKIE, $cookie );
}
curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, true );
curl_setopt( $ch, CURLOPT_HEADER, true );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch, CURLOPT_USERAGENT, $_GET['user_agent'] ? $_GET['user_agent'] : $_SERVER['HTTP_USER_AGENT'] );
list( $header, $contents ) = preg_split( '/([\r\n][\r\n])\\1/', curl_exec( $ch ), 2 );
$status = curl_getinfo( $ch );
curl_close( $ch );
}
// Split header text into an array.
$header_text = preg_split( '/[\r\n]+/', $header );
if ( $_GET['mode'] == 'native' ) {
if ( !$enable_native ) {
$contents = 'ERROR: invalid mode';
$status = array( 'http_code' => 'ERROR' );
}
// Propagate headers to response.
foreach ( $header_text as $header ) {
if ( preg_match( '/^(?:Content-Type|Content-Language|Set-Cookie):/i', $header ) ) {
header( $header );
}
}
print $contents;
} else {
// $data will be serialized into JSON data.
$data = array();
// Propagate all HTTP headers into the JSON data object.
if ( $_GET['full_headers'] ) {
$data['headers'] = array();
foreach ( $header_text as $header ) {
preg_match( '/^(.+?):\s+(.*)$/', $header, $matches );
if ( $matches ) {
$data['headers'][ $matches[1] ] = $matches[2];
}
}
}
// Propagate all cURL request / response info to the JSON data object.
if ( $_GET['full_status'] ) {
$data['status'] = $status;
} else {
$data['status'] = array();
$data['status']['http_code'] = $status['http_code'];
}
// Set the JSON data object contents, decoding it from JSON if possible.
$decoded_json = json_decode( $contents );
$data['contents'] = $decoded_json ? $decoded_json : $contents;
// Generate appropriate content-type header.
$is_xhr = strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest';
header( 'Content-type: application/' . ( $is_xhr ? 'json' : 'x-javascript' ) );
// Get JSONP callback.
$jsonp_callback = $enable_jsonp && isset($_GET['callback']) ? $_GET['callback'] : null;
// Generate JSON/JSONP string
$json = json_encode( $data );
print $jsonp_callback ? "$jsonp_callback($json)" : $json;
}
?>
我对 php 脚本的响应说状态代码为 0，内容为空，但如果我执行一个简单的 xmlhttp.status，它会显示 200。这个问题让我沮丧了一个星期。PHP脚本或我的ajax有问题，还是什么？