XMLHttpRequest 无法加载 http://127.0.0.1:1337/。请求的资源上不存在“Access-Control-Allow-Origin”标头[重复]

Posted 2023-02-27

【中文标题】XMLHttpRequest 无法加载 http://127.0.0.1:1337/。请求的资源上不存在“Access-Control-Allow-Origin”标头[重复]

【英文标题】：XMLHttpRequest cannot load http://127.0.0.1:1337/. No 'Access-Control-Allow-Origin' header is present on the requested resource [duplicate]

【发布时间】：2014-12-15 08:31:57

【问题描述】：

我尝试使用 Angular.js 和本地运行的 Node.js 服务器从 html 页面发送和接收数据

app.controller("MainController", function MainController($scope, $http)		
	$scope.postIt = function() 
		//alert("posting...");
		$http.post('http://127.0.0.1:1337/', msg:'hello from Angular.js!')
		.success(function onSuccess(response)
	        console.log(response);
	        $scope.$apply(function()
	            $scope.testData = JSON.parse(response);
	            console.log($scope.testData);
	        );
	    ).error(function onError()
	        console.log("AJAX failed!");
	    );
    ;
);	

<div id='content' 
     ng-app='MyTutorialApp' 
     ng-controller='MainController'>
	 <p>    
        <a ng-click="postIt()">
            Click here to load data.
        </a>
     </p>
</div>	
	<script src="bower_components/angular/angular.js" type="text/javascript"></script>
	<script src="app.js" type="text/javascript"></script>
	<script src="maincontroller.js" type="text/javascript"></script>

然后我得到错误：

 XMLHttpRequest cannot load http://127.0.0.1:1337/. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access.

我尝试将标题应用为app.js

var app = angular.module('MyTutorialApp', [], function($httpProvider) 
      $httpProvider.defaults.headers.post['Access-Control-Allow-Origin'] = 'http://127.0.0.1:1337/';
);

但这并没有生效。

Node.js 代码

var http = require('http');
http.createServer(function handler(req, res) 
    console.log(req.method, req.url, req.httpVersion, req.headers);

    res.writeHead(200, 'Content-Type': 'text/plain');
    res.end('Hello from Node.js\n');
).listen(1337, '127.0.0.1');
console.log('Server running at http://127.0.0.1:1337/');

【参考方案1】：

如果您使用 Angular 向您的 localhost node.js 服务器发送 ajax 请求，您应该将 access-control-allow-origin 放在接受 ajax 请求的目标服务器上，即 localhost，不要将其与 ajax 请求一起发布。