为什么Javascript XMLHttpRequest octet-stream MIME类型以字符串形式返回响应？

我试图用XMLHttpRequest获取gltf二进制文件.这是我试过的代码.

var xhr = new XMLHttpRequest();
xhr.open("GET","THE ADDRESS",true);
xhr.setRequestHeader("Accept", "application/octet-stream");
xhr.responseType = "arraybuffer";
xhr.onload = function (v) {
    resolve(xhr.response); // xhr.response must be ArrayBuffer but xhr.response is string
};
xhr.onerror = function (e) {
    reject(e);
};
xhr.send();

根据上面的代码,我肯定将responseType设置为arraybuffer.但是当onload处理程序调用时,responseType字段被更改为“”.

我在这段代码中没有调用任何其他“XMLHttpRequest.这是我得到的响应标题.

accept-ranges:bytes
content-length:102040
content-type:application/octet-stream
date:Fri, 18 Nov 2016 09:30:13 GMT
etag:"582ec3ef-18e98"
last-modified:Fri, 18 Nov 2016 09:03:43 GMT
server:h2o/2.0.4
status:200

这是我发送的请求标头.

:authority:localhost
:method:GET
:path:/gex/t90-01/Duck/Duck.bin
:scheme:https
accept:*/*
accept-encoding:gzip, deflate, sdch, br
accept-language:ja,en-US;q=0.8,en;q=0.6
cache-control:no-cache
pragma:no-cache
referer:https://localhost/gex/
user-agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36

任何帮助？

解决方法:

您可以通过使用overrideMimeType更改setRequestHeader来尝试以下代码,如下所示.

而且,你应该在你下面使用的解决方法中正确处理xhr.response,但不确定,你已经正确完成了.

var xhr = new XMLHttpRequest();
xhr.open("GET","THE ADDRESS",true);
xhr.overrideMimeType("application/octet-stream");
//xhr.setRequestHeader("Accept", "application/octet-stream");
xhr.responseType = "arraybuffer";
xhr.onload = function (v) {
    resolve(xhr.response); // xhr.response must be ArrayBuffer but xhr.response is string
};
xhr.onerror = function (e) {
    reject(e);
};
xhr.send();