js检测网址是否可访问，javascript检测网址是否可访问，支持跨域；

html 复制代码
<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>url检测是否可访问</title>
    <style>
    </style>
</head>
<body>
    <div id="km" style="font-size:23px;"></div>
    <script type="text/javascript">

        function getTimeDiff(startTime, endTime) {
            //var start = Date.parse(startTime);
            //var end = Date.parse(endTime);

            //var diff = Math.abs(end - start); // 返回时间差的毫秒数
            var diff = Math.abs(endTime - startTime); // 返回时间差的毫秒数
            return diff;
            //var seconds = Math.floor(diff / 1000);
            //var minutes = Math.floor(seconds / 60);
            //var hours = Math.floor(minutes / 60);
            //var days = Math.floor(hours / 24);

            // return days + "天 " + (hours % 24) + "小时 " + (minutes % 60) + "分钟 " + (seconds % 60) + "秒";
        }
 
        function importScript(sSrc, fOnload) {
            document.getElementById("km").innerHTML += "<br/>" + sSrc + "检测中....<br/>";
            var isConnected = false;
            var oScript = document.createElement("script");
            oScript.type = "text/javascript";
            var startTime = new Date();
            oScript.onerror = function (r) {
                var millisecond = getTimeDiff(startTime, new Date());
                console.log("连接出错-------------- " + sSrc);
                console.log(444, r);
                document.getElementById("km").innerHTML += "<br/>" + sSrc + "连接出错,耗时" + millisecond + "毫秒<br/>";
            };
            //if (fOnload) {
            //    oScript.onload = fOnload;
            //}
            oScript.onload = function (r) {
                var millisecond = getTimeDiff(startTime, new Date());
                isConnected = true;
                console.log("连接成功-------------- " + sSrc);
                console.log(555, r);
                document.getElementById("km").innerHTML += "<br/>" + sSrc + "连接成功,耗时" + millisecond + "毫秒<br/>";
            };
            document.currentScript.parentNode.insertBefore(
                oScript,
                document.currentScript,
            );
            oScript.src = sSrc;
            setTimeout(function () {
                //连接超时，触发
                if (!isConnected) {
                    console.log("连接超时-------------- " + sSrc);
                    var millisecond = getTimeDiff(startTime, new Date());
                    document.getElementById("km").innerHTML += "<br/>" + sSrc + "连接出错，超时，耗时" + millisecond + "毫秒<br/>";
                    //oScript.remove();
                    //window.location.href = "http://www.baidu.com";
                }
            }, 800);
        }
         
        !function () {          
            importScript("http://km.gg.com.cn:10081", function () { });
            importScript("http://km.bb.com.cn", function () { });
        }();
    </script>
</body>
</html>