You could use Undertow's HTTP/2 client, although it's API was designed
around the reverse proxy use case and as a result is not ideal for the
general purpose HTTP client use case (although it is still perfectly
usable).

In terms of using Undertow's ALPN implementation with Netty etc it
would require someone to port it over. The code is at [1] if you are
interested.

Stuart

[1] https://github.com/undertow-io/undertow/blob/master/core/src/main/java/io/undertow/protocols/ssl/ALPNHackSSLEngine.java

On Mon, Mar 20, 2017 at 7:21 AM, Steve Hu <stevehu@gmail.com> wrote:
> Thanks Stuart for the quick response. Now I have server started with HTTP/2
> and it works perfect with some client tools. Now I am looking for Java
> HTTP/2 client libraries to update my client module to support HTTP/2
> protocol for microservices communication. There are three major libraries
> okhttp, jetty and netty but all of them require Jetty's ALPN boot JAR. I saw
> you have resolved the boot jar dependency in Undertow and am wondering if
> you could point me to the right direction. Do you have any recommendation
> for HTTP/2 client library? How do you work around the alpn boot jar? Is the
> same solution can be used by okhttp, jetty and netty before Java 9 is
> released?
>
>
>
> On Fri, Mar 17, 2017 at 11:03 PM, Stuart Douglas <sdouglas@redhat.com>
> wrote:
>>
>> No, that is a debug level message. The JDK8 ALPN provider should still
>> be registered.
>>
>> Stuart
>>
>> On Sat, Mar 18, 2017 at 12:18 PM, Steve Hu <stevehu@gmail.com> wrote:
>> > Hi,
>> >
>> > I searched this mailing list and one post mentioned that I don't need to
>> > use
>> > -Xbootclasspath/p:<path_to_alpn_boot_jar> after 1.4.0Final. I am trying
>> > HTTP/2 on my server with 1.4.10 and Oracle JDK 1.8 but when I start the
>> > server I got the following error. Do I have to use OpenJDK 8? If I
>> > switch to
>> > JBoss OpenSSL implementation?
>> >
>> > Thanks,
>> >
>> > Steve
>> >
>> > 21:00:36.468 [main]  DEBUG io.undertow - Configuring listener with
>> > protocol
>> > HTTPS for interface 0.0.0.0 and port 8843
>> >
>> > 21:00:36.486 [main]  DEBUG io.undertow - JDK9 ALPN not supported
>> >
>> > java.lang.NoSuchMethodException:
>> > javax.net.ssl.SSLParameters.setApplicationProtocols([Ljava.lang.String;)
>> >
>> > at java.lang.Class.getMethod(Class.java:1786)
>> >
>> > at
>> >
>> > io.undertow.protocols.alpn.JDK9AlpnProvider$1.run(JDK9AlpnProvider.java:47)
>> >
>> > at
>> >
>> > io.undertow.protocols.alpn.JDK9AlpnProvider$1.run(JDK9AlpnProvider.java:43)
>> >
>> > at java.security.AccessController.doPrivileged(Native Method)
>> >
>> > at
>> >
>> > io.undertow.protocols.alpn.JDK9AlpnProvider.<clinit>(JDK9AlpnProvider.java:43)
>> >
>> > at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
>> >
>> > at
>> >
>> > sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
>> >
>> > at
>> >
>> > sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
>> >
>> > at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
>> >
>> > at java.lang.Class.newInstance(Class.java:442)
>> >
>> > at
>> > java.util.ServiceLoader$LazyIterator.nextService(ServiceLoader.java:380)
>> >
>> > at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:404)
>> >
>> > at java.util.ServiceLoader$1.next(ServiceLoader.java:480)
>> >
>> > at io.undertow.protocols.alpn.ALPNManager.<init>(ALPNManager.java:40)
>> >
>> > at io.undertow.protocols.alpn.ALPNManager.<clinit>(ALPNManager.java:35)
>> >
>> > at
>> >
>> > io.undertow.server.protocol.http.AlpnOpenListener.<init>(AlpnOpenListener.java:67)
>> >
>> > at
>> >
>> > io.undertow.server.protocol.http.AlpnOpenListener.<init>(AlpnOpenListener.java:90)
>> >
>> > at io.undertow.Undertow.start(Undertow.java:179)
>> >
>> > at com.networknt.server.Server.start(Server.java:170)
>> >
>> > at com.networknt.server.Server.main(Server.java:90)
>> >
>> > 21:00:36.503 [main]  INFO  com.networknt.server.Server - Https Server
>> > started on ip:0.0.0.0 Port:8843
>> >
>> >
>> > _______________________________________________
>> > undertow-dev mailing list
>> > undertow-dev@lists.jboss.org
>> > https://lists.jboss.org/mailman/listinfo/undertow-dev
>
>