Fwd: New ALPN API introduced in 8u252 vs. later JDKs' --release 8 support

[Andrew Hughes]

Seems like something more for 11u+ than 8u...

-------- Forwarded Message --------
Subject: New ALPN API introduced in 8u252 vs. later JDKs' --release 8
support
Date: Mon, 11 May 2020 14:46:40 +0200
From: Johannes Rudolph <johannes.rudolph at lightbend.com>
To: jdk8u-dev at openjdk.java.net

Hi there,

8u252 backported new APIs to support ALPN in TLS. We'd like to be able to
compile this code also with later JDKs using the `--release 8` flag.
However, that is currently not possible because the latest versions of
OpenJDK 11 does not (yet?) know about these new methods and compilation
fails on JDK 11:

λ /usr/lib/jvm/adoptopenjdk-11-hotspot-amd64/bin/javac --release 8 Test.java
Test.java:3: error: cannot find symbol
engine.setHandshakeApplicationProtocolSelector(null);
     ^
  symbol:   method setHandshakeApplicationProtocolSelector(<null>)
  location: variable engine of type SSLEngine

λ /usr/lib/jvm/adoptopenjdk-11-hotspot-amd64/bin/java --version
openjdk 11.0.7 2020-04-14
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.7+10)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.7+10, mixed mode)

Will the symbol lists that back the `--release` feature be updated? Or are
they a rather conservative approximation of what APIs older JDKs provide?
Who is driving the process to regenerate the symbol lists?

Workarounds would be not to compile on JDK 11 for now or to go back to a
reflection based approach for calling the new methods.

Johannes