netty.http2.NettyHttp2ClientInitializer.java Source code

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Here is the source code for netty.http2.NettyHttp2ClientInitializer.java

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package netty.http2;/*
                    * 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.
                    */

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.example.http2.helloworld.client.Http2ClientInitializer;
import io.netty.example.http2.helloworld.client.Http2SettingsHandler;
import io.netty.example.http2.helloworld.client.HttpResponseHandler;
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.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.Http2Connection;
import io.netty.handler.codec.http2.Http2FrameLogger;
import io.netty.handler.codec.http2.Http2Settings;
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 static io.netty.handler.logging.LogLevel.INFO;

/**
 * Configures the client pipeline to support HTTP/2 frames.
 */
public class NettyHttp2ClientInitializer extends ChannelInitializer<SocketChannel> {
    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 NettyHttp2ClientInitializer(SslContext sslCtx, int maxContentLength) {
        this.sslCtx = sslCtx;
        this.maxContentLength = maxContentLength;
    }

    @Override
    public void initChannel(SocketChannel ch) throws Exception {
        final Http2Connection connection = new DefaultHttp2Connection(false);
        final Http2Settings settings = new Http2Settings();
        settings.initialWindowSize(65535);
        settings.headerTableSize(4096);
        connectionHandler = new HttpToHttp2ConnectionHandlerBuilder()
                .frameListener(new DelegatingDecompressorFrameListener(connection,
                        new InboundHttp2ToHttpAdapterBuilder(connection).maxContentLength(maxContentLength)
                                .propagateSettings(true).build()))
                .frameLogger(logger).initialSettings(settings).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(new netty.http2.NettyHttpResponseHandler(), settingsHandler, responseHandler);
        pipeline.addLast(new NettyHttpResponseHandler(), new NettyHttpRequestHandler(), settingsHandler,
                responseHandler);
    }

    /**
     * Configure the pipeline for TLS NPN negotiation to HTTP/2.
     */
    private void configureSsl(SocketChannel ch) {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast(sslCtx.newHandler(ch.alloc()));
        // 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)) {
                    System.out.println("HTTP/2 Negotiated");
                    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();
        NettyHttp2ClientUpgradeCodec upgradeCodec = new NettyHttp2ClientUpgradeCodec(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.OPTIONS, "/");
            ctx.writeAndFlush(upgradeRequest).sync();

            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.err.println("User Event Triggered: " + evt);
            ctx.fireUserEventTriggered(evt);
        }
    }
}