EchoServerHandler.java

package com.github.nettybook.ch6;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

import java.nio.charset.Charset;

/**
 * Handler implementation for the echo server.
 */
public class EchoServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        ByteBuf readMessage = (ByteBuf) msg;
        System.out.println("channelRead : " + readMessage.toString(Charset.defaultCharset()));

        ByteBufAllocator byteBufAllocator = ctx.alloc();
        ByteBuf newBuffer = byteBufAllocator.buffer();
        
        // newBuffer 사용.

        ctx.write(msg);
    }

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