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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).
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/*
 * Copyright 2014 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License, version 2.0 (the
 * "License"); you may not use this file except in compliance with the License. You may obtain a
 * copy of the License at:
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package io.netty.example.http2.helloworld.client;

import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.DefaultFullHttpRequest;
import io.netty.handler.codec.http.HttpClientCodec;
import io.netty.handler.codec.http.HttpClientUpgradeHandler;
import io.netty.handler.codec.http.HttpHeaderNames;
import io.netty.handler.codec.http.HttpMethod;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.handler.codec.http2.DefaultHttp2Connection;
import io.netty.handler.codec.http2.DelegatingDecompressorFrameListener;
import io.netty.handler.codec.http2.Http2ClientUpgradeCodec;
import io.netty.handler.codec.http2.Http2Connection;
import io.netty.handler.codec.http2.Http2FrameLogger;
import io.netty.handler.codec.http2.HttpToHttp2ConnectionHandler;
import io.netty.handler.codec.http2.HttpToHttp2ConnectionHandlerBuilder;
import io.netty.handler.codec.http2.InboundHttp2ToHttpAdapterBuilder;
import io.netty.handler.ssl.ApplicationProtocolNames;
import io.netty.handler.ssl.ApplicationProtocolNegotiationHandler;
import io.netty.handler.ssl.SslContext;

import java.net.InetSocketAddress;

import static io.netty.handler.logging.LogLevel.INFO;

/**
 * Configures the client pipeline to support HTTP/2 frames.
 */
public class Http2ClientInitializer extends ChannelInitializer {
    private static final Http2FrameLogger logger = new Http2FrameLogger(INFO, Http2ClientInitializer.class);

    private final SslContext sslCtx;
    private final int maxContentLength;
    private HttpToHttp2ConnectionHandler connectionHandler;
    private HttpResponseHandler responseHandler;
    private Http2SettingsHandler settingsHandler;

    public Http2ClientInitializer(SslContext sslCtx, int maxContentLength) {
        this.sslCtx = sslCtx;
        this.maxContentLength = maxContentLength;
    }

    @Override
    public void initChannel(SocketChannel ch) throws Exception {
        final Http2Connection connection = new DefaultHttp2Connection(false);
        connectionHandler = new HttpToHttp2ConnectionHandlerBuilder()
                .frameListener(new DelegatingDecompressorFrameListener(
                        connection,
                        new InboundHttp2ToHttpAdapterBuilder(connection)
                                .maxContentLength(maxContentLength)
                                .propagateSettings(true)
                                .build()))
                .frameLogger(logger)
                .connection(connection)
                .build();
        responseHandler = new HttpResponseHandler();
        settingsHandler = new Http2SettingsHandler(ch.newPromise());
        if (sslCtx != null) {
            configureSsl(ch);
        } else {
            configureClearText(ch);
        }
    }

    public HttpResponseHandler responseHandler() {
        return responseHandler;
    }

    public Http2SettingsHandler settingsHandler() {
        return settingsHandler;
    }

    protected void configureEndOfPipeline(ChannelPipeline pipeline) {
        pipeline.addLast(settingsHandler, responseHandler);
    }

    /**
     * Configure the pipeline for TLS NPN negotiation to HTTP/2.
     */
    private void configureSsl(SocketChannel ch) {
        ChannelPipeline pipeline = ch.pipeline();
        // Specify Host in SSLContext New Handler to add TLS SNI Extension
        pipeline.addLast(sslCtx.newHandler(ch.alloc(), Http2Client.HOST, Http2Client.PORT));
        // We must wait for the handshake to finish and the protocol to be negotiated before configuring
        // the HTTP/2 components of the pipeline.
        pipeline.addLast(new ApplicationProtocolNegotiationHandler("") {
            @Override
            protected void configurePipeline(ChannelHandlerContext ctx, String protocol) {
                if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
                    ChannelPipeline p = ctx.pipeline();
                    p.addLast(connectionHandler);
                    configureEndOfPipeline(p);
                    return;
                }
                ctx.close();
                throw new IllegalStateException("unknown protocol: " + protocol);
            }
        });
    }

    /**
     * Configure the pipeline for a cleartext upgrade from HTTP to HTTP/2.
     */
    private void configureClearText(SocketChannel ch) {
        HttpClientCodec sourceCodec = new HttpClientCodec();
        Http2ClientUpgradeCodec upgradeCodec = new Http2ClientUpgradeCodec(connectionHandler);
        HttpClientUpgradeHandler upgradeHandler = new HttpClientUpgradeHandler(sourceCodec, upgradeCodec, 65536);

        ch.pipeline().addLast(sourceCodec,
                              upgradeHandler,
                              new UpgradeRequestHandler(),
                              new UserEventLogger());
    }

    /**
     * A handler that triggers the cleartext upgrade to HTTP/2 by sending an initial HTTP request.
     */
    private final class UpgradeRequestHandler extends ChannelInboundHandlerAdapter {

        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            DefaultFullHttpRequest upgradeRequest =
                    new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/", Unpooled.EMPTY_BUFFER);

            // Set HOST header as the remote peer may require it.
            InetSocketAddress remote = (InetSocketAddress) ctx.channel().remoteAddress();
            String hostString = remote.getHostString();
            if (hostString == null) {
                hostString = remote.getAddress().getHostAddress();
            }
            upgradeRequest.headers().set(HttpHeaderNames.HOST, hostString + ':' + remote.getPort());

            ctx.writeAndFlush(upgradeRequest);

            ctx.fireChannelActive();

            // Done with this handler, remove it from the pipeline.
            ctx.pipeline().remove(this);

            configureEndOfPipeline(ctx.pipeline());
        }
    }

    /**
     * Class that logs any User Events triggered on this channel.
     */
    private static class UserEventLogger extends ChannelInboundHandlerAdapter {
        @Override
        public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
            System.out.println("User Event Triggered: " + evt);
            ctx.fireUserEventTriggered(evt);
        }
    }
}