问题
I have a server endpoint that supports both HTTP/1.1 and HTTP2. For testing purposes, I want to try downloading content from the endpoint with both HTTP/1.1 and HTTP2 connections, possibly at the same time.
When I request data from the endpoint with an XMLHttpRequest, it automatically uses HTTP2, without me including the Connection: Upgrade header.
Is there a way to force an XMLHttpRequest to use HTTP/1.1 for the underlying TCP connection? What about other protocols, such as Quic or SPDY?
回答1:
No.
From Remy Lebeau's comment:
The browser decides which protocol it wants to use as an implementation detail of the XmlHttpRequest object. You can't force a particular choice from inside your script.
来源：https://stackoverflow.com/questions/56675358/is-there-a-way-to-force-an-xmlhttprequest-to-use-http-1-1