Question

我想通过URL传递获取json数据。但它显示的错误如

Failed to load https://sample-dec42.firebaseapp.com/one.json: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8082' is therefore not allowed access.

解决此错误我使用了以下服务器和控制器代码

控制器：

     $http.get('https://sample-dec42.firebaseapp.com/one.json').then( function(response) {
                          $scope.resultValue = response.data;
                          console.log('successful');
                        document.write(JSON.stringify(response));
                          console.log(  $scope.resultValue);


               });

app.js：

var request = require('request');
app.use(function(req,response,next)
{
    response.header('Access-Control-Allow-Origin',"*");
    response.header('Access-Control-Allow-Methods','GET,PUT,POST,DELETE,OPTIONS');
    response.header('Access-Control-Allow-Headers','Content-Type');
    next();


})

在这里，我创建了一个样本小提琴：Click Here to View

如何解决此错误。我在互联网上搜索过。但是，我仍然不知道为什么我一次又一次地得到这个错误。提前谢谢。

Answer 1

你可以试试这个：

将“cors”模块导入您的项目，如果您使用Express，请使用它：

app.use(cors());

Answer 2

使用以下代码::

app.use(function (req, res, next) {
// Following headers are needed for CORS
   res.setHeader('access-control-allow-headers', 'Origin, X-Requested-With, Content-Type, Accept, ajax, access-key,backend,app_request,frontend, token,device');
   res.setHeader('access-control-allow-methods', 'POST,HEAD,GET,PUT,DELETE,OPTIONS');
   res.setHeader('access-control-allow-origin', '*');
   next();
});

No＆＃39; Access-Control-Allow-Origin＆＃39;标头出现在请求的资源上。因此，不允许Origin＆＃39; localhost＆＃39;访问

2 个答案: