SPDY（读作"speedy"）是一个由谷歌开发的开放网络传输协议，旨在通过减少网页加载时间来加速网络通信。它最初在2009年被提出，并在2012年首次公开发布。SPDY设计用于减少网页内容加载的延迟，通过多路复用流、优先级排序、服务器推送等技术手段，提高网络传输效率。

SPDY并不是http的替代协议，而是对http1.1的补充升级，现已被http2替代。

在netty中依然提供了对SPDY协议的支持

如下：

java
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.spdy.SpdyFrameCodec;
import io.netty.handler.codec.spdy.SpdyHttpDecoder;
import io.netty.handler.codec.spdy.SpdyHttpEncoder;
import io.netty.handler.codec.spdy.SpdySessionHandler;
import io.netty.handler.ssl.ApplicationProtocolConfig;
import io.netty.handler.ssl.ApplicationProtocolNames;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.util.SelfSignedCertificate;

import javax.net.ssl.SSLException;
import java.security.cert.CertificateException;

public class SpdyServer {
    static final int PORT = Integer.parseInt(System.getProperty("port", "8443"));

    public static void main(String[] args) throws CertificateException, SSLException, InterruptedException {
        // 使用自签名证书
        SelfSignedCertificate ssc = new SelfSignedCertificate();
        SslContext sslCtx = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey())
                .applicationProtocolConfig(new ApplicationProtocolConfig(
                        ApplicationProtocolConfig.Protocol.NPN,
                        ApplicationProtocolConfig.SelectorFailureBehavior.NO_ADVERTISE,
                        ApplicationProtocolConfig.SelectedListenerFailureBehavior.ACCEPT,
                        ApplicationProtocolNames.SPDY_3_1))
                .build();

        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();

        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
             .channel(NioServerSocketChannel.class)
             .childHandler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 protected void initChannel(SocketChannel ch) {
                     ChannelPipeline pipeline = ch.pipeline();
                     pipeline.addLast(sslCtx.newHandler(ch.alloc()));
                     pipeline.addLast(new SpdyFrameCodec(SpdyVersion.SPDY_3_1));
                     pipeline.addLast(new SpdySessionHandler(SpdyVersion.SPDY_3_1, true));
                     pipeline.addLast(new SpdyHttpDecoder(SpdyVersion.SPDY_3_1, 8192));
                     pipeline.addLast(new SpdyHttpEncoder(SpdyVersion.SPDY_3_1));
                     pipeline.addLast(new SpdyServerHandler());
                 }
             });

            b.bind(PORT).sync().channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.spdy.SpdyHttpResponseStreamIdHandler;
import io.netty.handler.codec.spdy.SpdySessionHandler;
import io.netty.handler.codec.spdy.SpdyStreamFrame;

public class SpdyServerHandler extends SimpleChannelInboundHandler<SpdyStreamFrame> {
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, SpdyStreamFrame msg) throws Exception {
        System.out.println("Received SPDY frame: " + msg);
        ctx.writeAndFlush("Hello, SPDY");
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}