EchoClient.java

package com.manning.nettyinaction.chapter2;

import java.net.InetSocketAddress;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

/**
 * Listing 2.4  of <i>Netty in Action</i>
 *
 * @author <a href="mailto:norman.maurer@googlemail.com">Norman Maurer</a>
 */
public class EchoClient {

    private final String host;
    private final int port;

    public EchoClient(String host, int port) {
        this.host = host;
        this.port = port;
    }

    public void start() throws Exception {
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
             .channel(NioSocketChannel.class)
             .remoteAddress(new InetSocketAddress(host, port))
             .handler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 public void initChannel(SocketChannel ch) 
                     throws Exception {
                     ch.pipeline().addLast(
                             new EchoClientHandler());
                 }
             });

            ChannelFuture f = b.connect().sync();

            f.channel().closeFuture().sync();
        } finally {
            group.shutdownGracefully().sync();
        }
    }

    public static void main(String[] args) throws Exception {
        if (args.length != 2) {
            System.err.println(
                    "Usage: " + EchoClient.class.getSimpleName() +
                    " <host> <port>");
            return;
        }

        final String host = args[0];
        final int port = Integer.parseInt(args[1]);

        new EchoClient(host, port).start();
    }
}