指定 header 时，jQuery AJAX 无法工作(发出 OPTIONS 飞行前请求)

Question

AJAX 请求工作正常，但当我通过 beforeSend 或 headers 添加 header 时，会发出 OPTIONS 飞行前请求，并且 GET 请求将中止。

  Code: $.ajax({
        type: "GET",
        crossDomain: true,
         beforeSend: function (xhr)
         {
         xhr.setRequestHeader("session", $auth);
         },
        url: $url,
        success: function (data) {
            $('#something').html(data);
        },
        error: function (request, error) {
            $('#something').html("<p>Error getting values</p>");
        }
    });

类似未指定 header 的 AJAX 请求(当我添加/修改 header 时，会进行 OPTIONS 调用)

Request GET /api/something?filter=1 HTTP/1.1
Referer http://app.xyz.dj/dashboard
Accept  application/json, text/javascript, */*; q=0.01
Accept-Language en-US
Origin  http://app.xyz.dj
Accept-Encoding gzip, deflate
User-Agent  Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; MASMJS; rv:11.0) like Gecko
Host    162.243.13.172:8080
DNT 1
Connection  Keep-Alive
Cache-Control   no-cache

类似的服务器响应 header (用于 GET 请求)

Response    HTTP/1.1 200 OK
Server  Apache-Coyote/1.1
Access-Control-Allow-Origin *
Access-Control-Allow-Methods    GET, POST, DELETE, PUT, OPTIONS, HEAD
Access-Control-Allow-Headers    Content-Type, Accept, X-Requested-With
Access-Control-Allow-Credentials    true
Content-Type    application/json
Transfer-Encoding   chunked
Date    Thu, 09 Jan 2014 14:43:07 GMT

我做错了什么？

Answer 1

已解决。 感谢@JasonP 的指点。更改了服务器响应 header 自

Access-Control-Allow-Headers:*

具体的

Access-Control-Allow-Headers: Content-Type, Accept, X-Requested-With, Session

现在可以了!