How to add a handler to an HTTP client and read headers.

SampleAddHandler.java

package io.reactivex.netty.examples.http;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.HttpRequest;
import io.reactivex.netty.RxNetty;
import io.reactivex.netty.protocol.http.AbstractHttpContentHolder;
import io.reactivex.netty.protocol.http.client.HttpClient;
import io.reactivex.netty.protocol.http.client.HttpClientRequest;

import java.nio.charset.Charset;

public class SampleAddHandler {

    public static void main(String[] args) {

        RxNetty.createHttpServer(8088, (request, response) -> response.writeStringAndFlush("Hello")).start();

        HttpClient<ByteBuf, ByteBuf> client = RxNetty.<ByteBuf, ByteBuf>newHttpClientBuilder("localhost", 8088)
                .appendPipelineConfigurator(pipeline -> {
                    pipeline.addLast(new ChannelDuplexHandler() {
                        @Override
                        public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise)
                                throws Exception {
                            if (msg instanceof HttpRequest) {
                                HttpRequest request = (HttpRequest) msg;
                                String headerVal = request.headers().get("Req-Header");
                                System.out.println("Header val in handler: " + headerVal);
                            }
                            super.write(ctx, msg, promise);
                        }
                    });
                }).build();

        for (int i = 0; i < 4; i++) {
            HttpClientRequest<ByteBuf> request = HttpClientRequest.createGet("/hello");
            request.getHeaders().add("Req-Header", "value: " + i);
            client.submit(request)
                  .flatMap(AbstractHttpContentHolder::getContent)
                  .toBlocking()
                  .forEach(byteBuf -> System.out.println(byteBuf.toString(Charset.defaultCharset())));
        }
    }
}