jetty-alpn/jetty-alpn-server/src/main/config/etc/protonego-alpn.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_0.dtd">

<Configure id="protonego" class="org.eclipse.jetty.alpn.server.ALPNServerConnectionFactory">
    <Arg name="protocols">
        <Array type="String">
            <Item>spdy/3</Item>
            <Item>spdy/2</Item>
            <Item>http/1.1</Item>
        </Array>
    </Arg>

    <Set name="defaultProtocol">http/1.1</Set>

    <!-- Enables NPN debugging on System.err -->
    <!--<Set class="org.eclipse.jetty.alpn.ALPN" name="debug" type="boolean">true</Set>-->

</Configure>