Question

XMLHttpRequest无法加载https://opensky-network.org/api/states/all。请求中不存在“Access-Control-Allow-Origin”标头资源。因此，不允许原点'null'访问。

从api中检索数据时出现以下错误：

    <script>

      $.get('https://opensky-network.org/api/states/all', function(data) {
          console.log(data);
        });

  </script>

在头脑中我有这个：

 <script
        src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"
        integrity="sha256-hVVnYaiADRTO2PzUGmuLJr8BLUSjGIZsDYGmIJLv2b8="
        crossorigin="anonymous">
    </script>

整个代码如下所示：

<!DOCTYPE html>
<html>
  <head>
    <title>Geolocation</title>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <style>


      #map {
        height: 100%;
      }
      /* Optional: Makes the sample page fill the window. */
      html, body {
        height: 100%;
        margin: 0;
        padding: 0;
      }
    </style>


    <script
        src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"
        integrity="sha256-hVVnYaiADRTO2PzUGmuLJr8BLUSjGIZsDYGmIJLv2b8="
        crossorigin="anonymous">
    </script>


  </head>
  <body>
    <div id="map"></div>


    <script>


      function initMap() {
        var map = new google.maps.Map(document.getElementById('map'), {
          center: {lat: -34.397, lng: 150.644},
          zoom: 15,
           styles:
          [{"featureType":"all","elementType":"labels.text.fill","stylers":[{"saturation":36},{"color":"#000000"},{"lightness":40}]},{"featureType":"all","elementType":"labels.text.stroke","stylers":[{"visibility":"on"},{"color":"#000000"},{"lightness":16}]},{"featureType":"all","elementType":"labels.icon","stylers":[{"visibility":"off"}]},{"featureType":"administrative","elementType":"geometry.fill","stylers":[{"color":"#000000"},{"lightness":20}]},{"featureType":"administrative","elementType":"geometry.stroke","stylers":[{"color":"#000000"},{"lightness":17},{"weight":1.2}]},{"featureType":"landscape","elementType":"geometry","stylers":[{"color":"#000000"},{"lightness":20}]},{"featureType":"poi","elementType":"geometry","stylers":[{"color":"#000000"},{"lightness":21}]},{"featureType":"road.highway","elementType":"geometry.fill","stylers":[{"color":"#000000"},{"lightness":17}]},{"featureType":"road.highway","elementType":"geometry.stroke","stylers":[{"color":"#000000"},{"lightness":29},{"weight":0.2}]},{"featureType":"road.arterial","elementType":"geometry","stylers":[{"color":"#000000"},{"lightness":18}]},{"featureType":"road.local","elementType":"geometry","stylers":[{"color":"#000000"},{"lightness":16}]},{"featureType":"transit","elementType":"geometry","stylers":[{"color":"#000000"},{"lightness":19}]},{"featureType":"water","elementType":"geometry","stylers":[{"color":"#000000"},{"lightness":17}]}]

          });

        var infoWindow = new google.maps.InfoWindow({map: map});

        // Try HTML5 geolocation.
        if (navigator.geolocation) {
          navigator.geolocation.getCurrentPosition(function(position) {
            var pos = {
              lat: position.coords.latitude,
              lng: position.coords.longitude
            };

        var image = {
          url: 'icon.png',
          size: new google.maps.Size(80, 80),
          origin: new google.maps.Point(0, 0),
          anchor: new google.maps.Point(17, 34),
          scaledSize: new google.maps.Size(50, 50)
        }; 


        var marker = new google.maps.Marker({
          position: pos,
          animation: google.maps.Animation.DROP,
          map: map,
          icon: image,
        });


            infoWindow.setPosition(pos);
            infoWindow.setContent('U bevindt zich hier.');
            map.setCenter(pos);
          }, function() {
            handleLocationError(true, infoWindow, map.getCenter());
          });
        } else {
          // Browser doesn't support Geolocation
          handleLocationError(false, infoWindow, map.getCenter());
        }
      }



      function handleLocationError(browserHasGeolocation, infoWindow, pos) {
        infoWindow.setPosition(pos);
        infoWindow.setContent(browserHasGeolocation ?
                              'Error: The Geolocation service failed.' :
                              'Error: Your browser doesn\'t support geolocation.');
      }


    </script>

  <script>

      $.get('https://opensky-network.org/api/states/all', function(data) {
          console.log(data);
        });

  </script>

    <script async defer
    src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBCX-164-aso7Qtue97g_6kGdKVKkwN4SE&callback=initMap">
    </script>

  </body>
</html>

https://jsfiddle.net/ryo14gyk/

Answer 1

由于您的网页使用XMLHttpRequest对象从远程服务器发送和接收数据，因此您的脚本受same origin policy的约束。

因此，浏览器会阻止您的请求，因为脚本使其位于与服务器不同的域中。这是出于安全原因。

当您想要执行跨域请求时，您需要做一些不同的事情。其中一个＆＃34;清洁＆＃34;方法是在您的API级别enable CORS。

我很快就看到＆＃34; opensky-network＆＃34; API我注意到Java和Phyton的说明，但没有JavaScript的说明（同源策略适用于浏览器中的JS）。我建议你联系他们，询问他们是否有一些选项来启用CORS。

如果没有，替代方案是JSONP（如果他们允许）或PROXY，您可以自己构建并使用正确的标头返回API数据，这可以启用CORS通信。

Answer 2

这个错误因为api不允许任何人请求数据。您必须在请求时发送一些标头权限参数

没有'Access-Control-Allow-Origin'错误

2 个答案: