我有从外部网站加载的JSON脚本。在最简单的形式，在code一直是这样（和工作）：

I have a JSON script loaded from an external website. In its simplest form, the code has been like this (and working):

jQuery.getJSON("http://adressesok.posten.no/api/v1/postal_codes.json?postal_code=" + document.querySelector("input").value + "&callback=?",
    function(data){
        document.querySelector("output").textContent = data.postal_codes[0].city;
    });

不过，网站所有者不希望jQuery的，如果它不是关键的，所以我重新codeD .getJSON 到请求=新XMLHtt prequest（）; 型号：

request = new XMLHttpRequest();
request.open("GET", "http://adressesok.posten.no/api/v1/postal_codes.json?postal_code=" + document.querySelector("input").value + "&callback=?", true);
request.onload = function() {
    var data = JSON.parse(request.responseText);
    document.querySelector("output").textContent = data.postal_codes[0].city; 
};
request.onerror = function() { /* this gets called every time */ };

我修改我的code很多次，再读单证遍地，然而 .onerror 函数是唯一一个始终显示。这是控制台：

I've modified my code many times, read documentations over and over again, yet the .onerror function is the only one always displaying. This is the console:

这在挪威的说，这个剧本要求CORS，它无法找到访问控制 - 允许 - 原产地的负责人的起源，那XMLHtt prequest了网络错误，并说不访问。

Which in Norwegian says that this script requested CORS, that it can't find the origin in the head of Access-Control-Allow-Origin, and that the XMLHttpRequest had a network error, and says "no access".

这可能有几个原因，为什么出现这种情况：

There could be several reasons as to why this occurs:

1 有什么毛病了新的code

1: There's something wrong with the new code

2 有什么东西在 .getJSON jQuery函数（？黑客攻击）是$ P $的发生pvents错误

2: There's something in the .getJSON jQuery function (a hack?) that prevents the error from happening

3 有什么东西在新的code，我已经忘了添加关键

3: There's something crucial in the new code that I have forgot adding

4：有一些与我的浏览器（IE 11的那一刻）

4: There's something with my browser (IE 11 at the moment)

5：别的东西

这将是可爱的有一些这方面的帮助。

It would be lovely with some help on this.

演示： http://jsbin.com/muxigulegi/1/

推荐答案

这是不是网络错误。这是一个跨起源错误。该请求是成功的，但在浏览器拒绝访问响应你的JavaScript。

That isn't a network error. It's a cross origin error. The request is successful but the browser is denying access to the response to your JavaScript.

既然你有回调=？的URL，jQuery将产生一个JSONP请求，而不是一个XMLHtt prequest请求。这执行响应作为脚本而不是读的原始数据。

Since you have callback=? in the URL, jQuery will generate a JSONP request instead of an XMLHttpRequest request. This executes the response as a script instead of reading the raw data.

您手动创建一个XMLHtt prequest，所以失败是由于同源策略。

You are manually creating an XMLHttpRequest, so it fails due to the Same Origin Policy.

Create一个JSONP请求代替。