contentType：'application / json'和POST方法（JavaScript） [英] contentType: 'application/json' with POST method (JavaScript)

问题描述

我需要用JavaScript创建一个Web服务器客户端，我在定义Request头时遇到了一些问题。

I need to create a web server client in JavaScript and I have some problems to define Request headers.

我需要POST方法和Content-Type：application / json。

I need POST method and Content-Type: "application/json".

我试过这个：

    $.ajax({
            url: 'http://MyWebServiceAddress',
            data: JSON.stringify({user:'user',pass:'pass'}),
            type: 'POST',
            crossDomain: true,
            dataType: 'json',
            success: function () {
                    alert("success")
            },
            error: function (xhr, ajaxOptions, thrownError) {
                alert("Error: " + xhr.status + "\n" +
                        "Message: " + xhr.statusText + "\n" +
                        "Response: " + xhr.responseText + "\n" + thrownError);
            }
        });

但如果我把contentType这样：

But if I put contentType like this:

contentType：'application / json; charset = utf-8'，

contentType: 'application/json; charset=utf-8',

然后查看Chrome开发工具的请求我可以看到该方法已更改为OPTIONS并输入text / plain

and look then the request with Chrome Dev Tools I can see that method was changed to "OPTIONS" and type to "text/plain"

任何人都可以帮助我吗？我不必使用Ajax，所以如果有人知道一个好的JavaScript库以使客户端更容易，可能会导致我的问题

Anyone can help me? I don't have to use Ajax, so if someone know a good JavaScript library to make client easier, maybe can result my problems

推荐答案

你需要像你写的一样设置 contentType 标题; contentType 用于请求本身，而 dataType 标头用于您希望从服务器返回的响应。因此，如果您将 contentType 添加到 $。ajax 请求，它看起来是正确的。

You do need to set the contentType header just as you've written; the contentType is for the request itself, while the dataType header is for the response you're expecting back from the server. So if you add that contentType to the $.ajax request, it looks correct.

OPTIONS请求是一个不同的问题：因为你必须发出跨域请求而发送，这意味着ajax请求的服务地址（ http：/ / MyWebServiceAddress ）与当前页面的origin地址不同。是这样的吗？一个例子是，如果您的页面来自 http://example.com ，并且您正在向 http://twitter.com发出请求来自该页面。您可以在此处了解有关跨源或CORS请求的更多信息。底线是 $ .ajax 必须在发布JSON数据之前发出单独的ORIGIN请求，然后它会发出POST请求 - 当且仅当服务器 http：// MyWebServiceAddress 配置为允许来自您网页域的CORS请求时。有关更多详细信息，请参阅上面的CORS链接。

The "OPTIONS" request is a different issue: that's being sent because you must be making a "cross-origin" request, meaning the ajax request's service address (http://MyWebServiceAddress) is different from the current page's "origin" address. Is that the case? An example would be if your page comes from http://example.com, and you are making a request to http://twitter.com from that page. You can read more about cross-origin, or CORS, requests here. The bottom line is that $.ajax has to make a separate ORIGIN request before posting JSON data like you're doing, and then it will make the POST request -- if and only if the server at http://MyWebServiceAddress is configured to allow CORS requests from your page's domain. See that CORS link above for more details.

这篇关于contentType：'application / json'和POST方法（JavaScript）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！