HTTP/2 Java 8, Jetty and ALPN

Question

I went thru this page: https://www.eclipse.org/jetty/documentation/9.3.x/alpn-chapter.html to have an ALPN boot jar in my classpath and still I can't get it working.

I am confused as to know if I need an Open SDK Java 8 than Oracle Java 8.

My Java version is:

java -version
java version "1.8.0_11"
Java(TM) SE Runtime Environment (build 1.8.0_11-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.11-b03, mixed mode)

And I'm using the following versions of Jetty and ALPN boot:

<jetty-version>9.4.0.M1</jetty-version>
<alpn-version>8.1.9.v20160720</alpn-version>    
<dependency>
        <groupId>org.mortbay.jetty.alpn</groupId>
        <artifactId>alpn-boot</artifactId>
        <version>${alpn-version}</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-client</artifactId>
    <version>${jetty-version}</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jetty.http2</groupId>
    <artifactId>http2-client</artifactId>
    <version>${jetty-version}</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jetty.http2</groupId>
    <artifactId>http2-http-client-transport</artifactId>
    <version>${jetty-version}</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jetty.http2</groupId>
    <artifactId>http2-common</artifactId>
    <version>${jetty-version}</version>
</dependency>
<dependency>
    <groupId>org.eclipse.jetty.http2</groupId>
    <artifactId>http2-hpack</artifactId>
    <version>${jetty-version}</version>
</dependency>

Also I tried using different versions of Jetty and ALPN which I found here https://mvnrepository.com/artifact/org.mortbay.jetty.alpn/alpn-boot and here https://mvnrepository.com/search?q=org.eclipse.jetty

Whichever ways I tried I never got it working submitting a POST request to an HTTP/2 endpoint.

However with Netty and the following dependency my tests were successful:

<dependency>
           <groupId>io.netty</groupId>
           <artifactId>netty-tcnative-boringssl-static</artifactId>
           <version>1.1.33.Fork22</version>
       </dependency>

Where do I find the documentation to see which version of ALPN boot is compatible with Oracle JDK? Is ALPN boot only compatible with OpenJDK?

I read that starting Java 9 support for ALPN will be native.

On a side note, which one is better? Netty or Jetty for HTTP/2 calls.

Answer 1

Netty is preferred for several reasons for making Http/2 connections. Few advantages I have seen using it are :

• No need for the ALPN jar to be added to the boot classpath. Adding maven dependency "netty-tcnative-boringssl-static" does the job
• It inherently support a asynchronous model of using the API. Hence it makes it simpler to handle data pushed by the server in case of HTTP/2