javascript - 发出 PUT 请求会导致在 PUT 之前先发送 OPTIONS 请求，为什么浏览器会这样？

Question

当我发送 POST 请求时，没问题。但是当我发送一个 PUT 请求(将 $http.post() 替换为 $http.put())时，Angular 发送一个没有数据的 OPTIONS 请求，等待响应并发送一个带有数据的 PUT 请求。

这不是 CORPS 问题，因为是客户端发送了 2 个请求。

对于 OPTIONS 请求，JSON 响应没有被解析，因为 Angular 没有进入成功函数。

我想让 Angular 不发送 OPTIONS 请求。你知道这个问题吗？你知道解决办法吗？

代码:

var app = angular.module('myApp', []);
app.config(function($httpProvider) {
    delete $httpProvider.defaults.headers.common['X-Requested-With'];
    $httpProvider.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded; charset=UTF-8';
    $httpProvider.defaults.headers.put['Content-Type'] = 'application/x-www-form-urlencoded; charset=UTF-8';
    $httpProvider.defaults.useXDomain = true;
    //
    var param = function(obj) {
        var query = '', name, value, fullSubName, subName, subValue, innerObj, i;
        for(name in obj) {
            value = obj[name];
            if(value instanceof Array) {
                for(i=0; i<value.length; ++i) {
                    subValue = value[i];
                    fullSubName = name + '[' + i + ']';
                    innerObj = {};
                    innerObj[fullSubName] = subValue;
                    query += param(innerObj) + '&';
                }
            }
            else if(value instanceof Object) {
                for(subName in value) {
                    subValue = value[subName];
                    fullSubName = name + '[' + subName + ']';
                    innerObj = {};
                    innerObj[fullSubName] = subValue;
                    query += param(innerObj) + '&';
                }
            }
            else if(value !== undefined && value !== null) {
                query += encodeURIComponent(name) + '=' + encodeURIComponent(value) + '&';
            }
        }
        return query.length ? query.substr(0, query.length - 1) : query;
    };
    // Override $http service's default transformRequest (json to application/x-www-form-urlencoded)
    $httpProvider.defaults.transformRequest = [function(data) {
        return angular.isObject(data) && String(data) !== '[object File]' ? param(data) : data;
    }];
});
app.controller('login', function ($scope, $http) {
    $scope.run = function() {
        var file_data = $("#file").prop("files")[0];
        var datas = {email:"email@domain.com", pass:sha1("xxxxxx")};
        $http.put("http://myapi.com/user/connect", datas
            ).success(function(data, status, headers, config) {
                console.log(data);
            }).error(function(data, status, headers, config) {

            });
        return;
    }
});

第一个请求:

General
Remote Address:127.0.0.1:80
Request URL:http://api.wezit.local/user/connect
Request Method:OPTIONS
Status Code:200 OK

Response Headers
Access-Control-Allow-Methods:POST, GET, PUT, DELETE
Access-Control-Allow-Origin:*
Cache-Control:no-cache, must-revalidate
Connection:Keep-Alive
Content-Length:170
Content-Type:application/json;
Date:Fri, 17 Jul 2015 16:31:15 GMT
Expires:Mon, 26 Jul 1997 05:00:00 GMT
Keep-Alive:timeout=5, max=100
Pragma:no-cache
Server:Apache/2.4.10 (Fedora) PHP/5.5.25
Set-Cookie:PHPSESSID=2dj440b2vr2emi5ht9ojcl8gk6; path=/
Set-Cookie:PHPSESSID=q3pg80qb43ps6tpkljlvelo0k7; path=/
X-Powered-By:PHP/5.5.25

Request Headers
Accept:*/*
Accept-Encoding:gzip, deflate, sdch
Accept-Language:fr-FR,fr;q=0.8,en-US;q=0.6,en;q=0.4
Access-Control-Request-Headers:accept, content-type
Access-Control-Request-Method:PUT
Connection:keep-alive
Host:api.wezit.local
Origin:http://test.local
Referer:http://test.local/api.php
User-Agent:Mozilla/5.0 (X11; Linux i686 (x86_64)) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.125 Safari/537.36

第二个请求:

General
Remote Address:127.0.0.1:80
Request URL:http://api.wezit.local/user/connect
Request Method:PUT
Status Code:200 OK

Response Headers
Access-Control-Allow-Methods:POST, GET, PUT, DELETE
Access-Control-Allow-Origin:*
Cache-Control:no-cache, must-revalidate
Connection:Keep-Alive
Content-Length:327
Content-Type:application/json;
Date:Fri, 17 Jul 2015 16:31:15 GMT
Expires:Mon, 26 Jul 1997 05:00:00 GMT
Keep-Alive:timeout=5, max=99
Pragma:no-cache
Server:Apache/2.4.10 (Fedora) PHP/5.5.25
Set-Cookie:PHPSESSID=18jfhgq2fs1p1f1nu7ua1ap8c3; path=/
Set-Cookie:PHPSESSID=14aifglpntf8amavkipclvom67; path=/
X-Powered-By:PHP/5.5.25

Request Headers
Accept:application/json, text/plain, */*
Accept-Encoding:gzip, deflate, sdch
Accept-Language:fr-FR,fr;q=0.8,en-US;q=0.6,en;q=0.4
Connection:keep-alive
Content-Length:142
Content-Type:application/x-www-form-urlencoded; charset=UTF-8
Host:api.wezit.local
Origin:http://test.local
Referer:http://test.local/api.php
User-Agent:Mozilla/5.0 (X11; Linux i686 (x86_64)) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.125 Safari/537.36

Form Data
email:email@domain.com
pass:ce35927f4dcb044bceda5f385823419cb0156507

Answer 1

当您发起跨源请求时，浏览器总是使用 OPTION 方法进行飞行前请求。这意味着您尝试访问的 API 与您的应用程序来源不同。您对此无能为力。

Do you know this problem?

您观察到的没有问题，这是预期的行为。

When i send a POST request, it's OK.

Here's the reason why it's OK :

In particular, a request is preflighted if:

• It uses methods other than GET, HEAD or POST. Also, if POST is used to send request data with a Content-Type other than application/x-www-form-urlencoded, multipart/form-data, or text/plain, e.g. if the POST request sends an XML payload to the server using application/xml or text/xml, then the request is preflighted.
• It sets custom headers in the request (e.g. the request uses a header such as X-PINGOTHER)