EchoServerHandlerWithFuture.java

package com.github.nettybook.ch5;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

/**
 * Handler implementation for the echo server.
 */
@Sharable
public class EchoServerHandlerWithFuture extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        ChannelFuture channelFuture = ctx.writeAndFlush(msg);

        final int writeMessageSize = ((ByteBuf) msg).readableBytes();

        channelFuture.addListener(new ChannelFutureListener() {
            @Override
            public void operationComplete(ChannelFuture future) throws Exception {
                System.out.println("전송한 Byte : " + writeMessageSize);
                future.channel().close();
            }
        });
    }

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