[WIP] Jetty HTTP2 Support

[olamy]

This pr had Jetty HTTP2 support for the project.
Still WIP as I'm not sure what is your preferences in term of configuration..
Have a look at the new bean Http2.
Let me know. Then I will add unit test etc..
A sample project is available here https://github.com/olamy/jetty-http2-springboot

[bclozel]

Hi @olamy, thanks a lot for this PR; as you can see in #10043, we have quite a few contributions already and we first need to figure out a global approach before we can resume with those.

As far as I understand, Jetty is using a Java agent to avoid doing the whole boot classpath thing. I'm not aware of any other solution involving something like native bindings. Am I right?

Feel free to comment on #10043 - thanks!

[olamy]

Hi @bclozel
Correct Jetty doesn't need any native binding.
You can find some details here: https://www.eclipse.org/jetty/documentation/current/alpn-chapter.html
The agent (https://github.com/jetty-project/jetty-alpn-agent) is a convenient way for users as it will choose automatically the correct alpn boot to use otherwise users need to download the version depending on their java version.

[bclozel]

Jetty is about to support native bindings with Conscrypt, which avoids messing with the boot classpath and using a Java agent - much more in line with the usual java -jar Spring Boot experience.

We'll definitely cherry-pick things from this PR. Thanks @olamy !

Closing this in favor of #10902