我正在本地服务器上运行Google Super Proxy项目，并尝试提取从Google appspot网站托管的JSON查询数据。
http://userTest.appspot.com/query?id=ahJzfmNvbm5vcnBoSDfsFEWDSDxsaXBzMjRyFQsSCEFwaVF1ZXJ5GICAgICAgIAKDA
我一直遇到的问题是，由于我没有CORS支持，因此不允许我从本地服务器访问此网页。我已经尝试使用JavaScript和JQuery来启用CORS支持，但是在控制台中仍然出现两条错误消息。有人知道有什么帮助吗？
1）
Failed to load resource: the server responded with a status of 405 (Method Not Allowed) http://userTest.appspot.com/query?id=ahJzfmNvbm5vcnBoaWEEWWEWxsaXBzMjRyFQsSCEFwaVF1ZXJ5GICAgICAgIAKDA
2）
XMLHttpRequest cannot load http://userTest.appspot.com/query?id=ahJzfmNvbm5vcnBoaWxsaXBzMjREWEADSdyFQsSCEFwaVF1ZXJ5GICAgICAgIAKDA. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8888' is therefore not allowed access.
index.html：
<!doctype html>
<html>
<head>
<title>Google Super Proxy Test</title>
<script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="chart-options.js"></script>
<script src="Chart.min.js"></script>
</head>
<body>
<div style="width: 50%">
<canvas id="sessions-graph" height="450" width="600"></canvas>
</div>
</body>
</html>
chart-options.js：
$.ajax({
type: 'GET',
url: 'http://userTest.appspot.com/query?id=ahJzfmNvbm5vcnBoaWxsaXBzMSDFSDFSjRyFQsSCEFwaVF1ZXJ5GICAgICAgIAKDA',
contentType: 'json',
crossDomain: true,
headers: { 'Access-Control-Allow-Origin': '*'},
success: function(data) {
$.each(data, function(index, element) {
alert(element.name);
})
},
xhrFields: {
withCredentials: true
},
error: function (json) {
debugger;
}
});
var barChartdata = {
labels: [],
datasets: [
{
label: "My First dataset",
fillColor: "rgba(220,220,220,0.5)",
strokeColor: "rgba(220,220,220,0.8)",
highlightFill: "rgba(220,220,220,0.75)",
highlightStroke: "rgba(220,220,220,1)",
data: []
}
]
};
var options = {
//Boolean - Whether the scale should start at zero, or an order of magnitude down from the lowest value
scaleBeginAtZero : true,
//Boolean - Whether grid lines are shown across the chart
scaleShowGridLines : true,
//String - Colour of the grid lines
scaleGridLineColor : "rgba(0,0,0,.05)",
//Number - Width of the grid lines
scaleGridLineWidth : 1,
//Boolean - If there is a stroke on each bar
barShowStroke : true,
//Number - Pixel width of the bar stroke
barStrokeWidth : 2,
//Number - Spacing between each of the X value sets
barValueSpacing : 5,
//Number - Spacing between data sets within X values
barDatasetSpacing : 1,
//Boolean - Set if responsive or not
responsive : true
}
window.onload = function(){
// Get the context of the canvas element
var ctx = document.getElementById("sessions-graph").getContext("2d");
var sessionsGraph = new Chart(ctx).Bar(barChartdata, options); //Create a chart with "data" array
};
最佳答案
Access-Control-Allow-Origin是响应头。
您要求提供数据的服务器必须在HTTP响应中提供数据。编辑负责生成http://userTest.appspot.com/query的代码以包含它。
它不属于请求标头。您的脚本无法授予自己访问任何网站的权限。
通过使其成为请求标头，可以触发预检OPTIONS请求（这可能是导致您的方法不允许错误的原因）。