Ajax请求上为什么出错误了？

Question

我在Ajax请求上遇到了麻烦，我得到了以下错误：

Error: Access is denied

我尝试了这个jQueryAjax请求：

$.support.cors = true;
$.ajax({
    url: 'http://testwebsite.com/test',
    type: "GET",
    dataType: 'json',
    contentType: 'application/json',
    crossDomain: true,
    headers: {
        'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',
        'Access-Control-Allow-Origin': 'http://testwebsite/test',
        'Access-Control-Allow-Headers': '*',
        'Access-Control-Allow-Credentials': 'true'
    },
    xhrFields: {
        withCredentials: true
    },
    success: function(data) {
        alert("Data from Server" + JSON.stringify(data));
    },
    error: function(jqXHR, textStatus, errorThrown) {
        alert("You can not send Cross Domain AJAX requests: " + errorThrown);
    }
});

谁能告诉我哪里出错了？提前谢谢你。

Answer 1

As rory-mccrossan mentioned in a comment, CORS protection is designed so that a website cannot directly access the content of another website (in a browser) unless the website being accessed agrees to it.

It would completely ruin the point of CORS if a site just has to send some headers in order to circumvent the defence

Instead, you will need to use a CORS proxy. It's a server that when given a request like yourCORSproxy.example.com/http://testwebsite/test would load the page and return it, but with CORS allowed (like a normal proxy but with CORS enabled).

One of these CORS proxies is https://crossorigin.me, but at the time of writing this it is down. It might be more stable if you simply create your own proxy.

---

tl;dr: testsite.test should be sending the headers on its response. You should not be sending the headers on your request.