Http2Client.java

package chapter7.recipe1.client;

import static io.netty.handler.codec.http.HttpMethod.GET;
import static io.netty.handler.codec.http.HttpMethod.POST;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.http.DefaultFullHttpRequest;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.HttpHeaderNames;
import io.netty.handler.codec.http.HttpHeaderValues;
import io.netty.util.CharsetUtil;

import java.net.URI;
import java.util.concurrent.TimeUnit;

/**
 * An HTTP2 client that allows you to send HTTP2 frames to a server. Inbound and outbound frames are
 * logged. When run from the command-line, sends a single HEADERS frame to the server and gets back
 * a "Hello World" response.
 */
public final class Http2Client {

    static final boolean SSL = System.getProperty("ssl") != null;
    static final String HOST = System.getProperty("host", "127.0.0.1");
    static final int PORT = Integer.parseInt(System.getProperty("port", SSL? "8443" : "8080"));
    static final String URL = System.getProperty("url", "/whatever");
    static final String URL2 = System.getProperty("url2");
    static final String URL2DATA = System.getProperty("url2data", "test data!");

    public static void main(String[] args) throws Exception {
    	
    	 EventLoopGroup workerGroup = new NioEventLoopGroup();
         Http2ClientInitializer initializer = new Http2ClientInitializer(Integer.MAX_VALUE);

         try {
             // Configure the client.
             Bootstrap b = new Bootstrap();
             b.group(workerGroup);
             b.channel(NioSocketChannel.class);
             b.option(ChannelOption.SO_KEEPALIVE, true);
             b.remoteAddress(HOST, PORT);
             b.handler(initializer);

             // Start the client.
             Channel channel = b.connect().syncUninterruptibly().channel();
             System.out.println("Connected to [" + HOST + ':' + PORT + ']');

             // Wait for the HTTP/2 upgrade to occur.
             Http2SettingsHandler http2SettingsHandler = initializer.settingsHandler();
             http2SettingsHandler.awaitSettings(5, TimeUnit.SECONDS);

             HttpResponseHandler responseHandler = initializer.responseHandler();
             int streamId = 3;
             URI hostName = URI.create((SSL ? "https" : "http") + "://" + HOST + ':' + PORT);
             System.err.println("Sending request(s)...");
             if (URL != null) {
                 // Create a simple GET request.
                 FullHttpRequest request = new DefaultFullHttpRequest(HTTP_1_1, GET, URL);
                 request.headers().addObject(HttpHeaderNames.HOST, hostName);
                 request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);
                 request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.DEFLATE);
                 channel.writeAndFlush(request);
                 responseHandler.put(streamId, channel.newPromise());
                 streamId += 2;
             }
             if (URL2 != null) {
                 // Create a simple POST request with a body.
                 FullHttpRequest request = new DefaultFullHttpRequest(HTTP_1_1, POST, URL2,
                                 Unpooled.copiedBuffer(URL2DATA.getBytes(CharsetUtil.UTF_8)));
                 request.headers().addObject(HttpHeaderNames.HOST, hostName);
                 request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);
                 request.headers().add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.DEFLATE);
                 channel.writeAndFlush(request);
                 responseHandler.put(streamId, channel.newPromise());
                 streamId += 2;
             }
             responseHandler.awaitResponses(5, TimeUnit.SECONDS);
             System.out.println("Finished HTTP/2 request(s)");

             // Wait until the connection is closed.
             channel.close().syncUninterruptibly();
         } finally {
             workerGroup.shutdownGracefully();
         }
    }
}