Question

我正在尝试使用javascript / jquery获取通过api提供的mp3文件的文件大小。当我在控制台中运行以下代码时：

function getFileSize(url, callback) {
    var request = new XMLHttpRequest();
    //get only header.
    request.open("HEAD", url, true);
    request.onreadystatechange = function() {
        if (this.readyState == this.DONE) {
            callback(parseInt(request.getResponseHeader("Content-Length")));
        }
    };
    request.send();
}

//Example: Coldplay - Adventure of a Lifetime, 04:18 duration (280 in seconds)
getFileSize("https://datmusic.xyz/stream/nRPk:X3E3gB", function(sizeInBytes){
    duration = 280; //seconds
    bitrate = sizeInBytes / duration;
    console.log("~" + bitrate + " kbps")
})

有时会返回正确的值

~36959.53214285714 kbps

但大部分时间都会返回

XMLHttpRequest cannot load https://datmusic.xyz/stream/nRPk:X3E3gB. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://butane.stereostance.com' is therefore not allowed access.
    VM109:17 ~NaN kbps

即使只刷新相同的标签并重新运行代码也会产生不同的结果。如何获得一致的结果，最重要的是获取文件大小？

编辑：

Proof of running on different domain

Exact same page in a different tab, not returning value

通过Content-Length请求文件大小有时会有效，有时也不会

0 个答案: