Java HTTP/2 Server Socket

Question

I want to get server sockets working for HTTP/2 in Java, preferably TLS/https.

I've got a TLS server socket working fine, but browsers will only talk HTTP/1.1 to it. If I understand correctly, you need ALPN to get a HTTP/2 browser to connect to your TLS socket and start running HTTP/2 on it; browsers won't ask for upgrade to HTTP/2 on https. It seems Java8 does not do ALPN so far. Maybe there is some other way to coerce browsers to do HTTP/2, at least non-TLS.

So, anybody know how to make a Java server socket for HTTP/2?

Answer 1

Java won't get ALPN until at least JDK 9, which is slated for late 2016 or 2017.

Meanwhile, you can use Jetty's ALPN implementation, or better yet, use Jetty (or other servers as suggested) directly rather than doing your own HTTP/2 implementation using ServerSocket.

[Disclaimer, I am a Jetty committer] Jetty 9.3 has great support for HTTP/2, including HTTP/2 Push.

Answer 2

FYI, Java Dev Team is preparing ALPN for Java 9. Hopefully as you can see this issue, https://bugs.openjdk.java.net/browse/JDK-8062848,

ALPN support may be backported to JDK 8 so an implementation is needed that does not introduce any new Java SE APIs. This may require creating something in a com.oracle.ssl.net package or via System Properties.