NettyServerHandler

package com.ctgu.netty.basic;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

public class NettyServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        ctx.close();
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        System.out.println("Server:" + ctx);
        System.out.println("ServerMsg:" + msg);
        ByteBuf buf = (ByteBuf) msg;
        try {
            String str = BufDecoder.buf2string(buf);
            if (str.length() > 0) {
                System.out.println("客户端发来的消息:" + str);
                System.out.flush();
            } else {
                System.out.println("不能读啊");
            }
        } finally {
            buf.release();
        }
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.writeAndFlush(Unpooled.copiedBuffer("就是没钱", CharsetUtil.UTF_8));
    }
}

NettyServer

package com.ctgu.netty.basic;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;

public class NettyServer {
    public static void main(String[] args) throws InterruptedException {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        ServerBootstrap b = new ServerBootstrap();
        b.group(bossGroup, workerGroup);
        b.channel(NioServerSocketChannel.class);
        b.option(ChannelOption.SO_BACKLOG, 128);
        b.childOption(ChannelOption.SO_KEEPALIVE, true);
        b.childHandler(new ChannelInitializer<SocketChannel>() {
            @Override
            protected void initChannel(SocketChannel sc) throws Exception {
                sc.pipeline().addLast(new NettyServerHandler());
            }
        });
        System.out.println("-------Server is ready--------");
        ChannelFuture cf = b.bind(9999).sync();
        System.out.println("-------Server is starting--------");
        cf.channel().closeFuture().sync();
        bossGroup.shutdownGracefully();
        workerGroup.shutdownGracefully();
    }
}

NettyClientHandler

package com.ctgu.netty.basic;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;


public class NettyClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("Client:" + ctx);
        ctx.writeAndFlush(Unpooled.copiedBuffer("老板，快还钱", CharsetUtil.UTF_8));
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf buf = (ByteBuf) msg;
        System.out.println("服务端发来的消息:" + BufDecoder.buf2string(buf));
    }

}

NettyClient

package com.ctgu.netty.basic;

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;

public class NettyClient {
    public static void main(String[] args) throws InterruptedException {
        EventLoopGroup group = new NioEventLoopGroup();
        Bootstrap b = new Bootstrap();
        b.group(group)
                .channel(NioSocketChannel.class)
                .handler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    protected void initChannel(SocketChannel sc) throws Exception {
                        sc.pipeline().addLast(new NettyClientHandler());
                    }
                });
        System.out.println("----------Client is ready--------");
        ChannelFuture cf = b.connect("127.0.0.1", 9999);
        System.out.println("----------Client is Starting--------");
        cf.channel().closeFuture().sync();
        group.shutdownGracefully();
    }
}

BufDecoder

package com.ctgu.netty.basic;

import io.netty.buffer.ByteBuf;

public class BufDecoder {
    public static String buf2string(ByteBuf buf) {
        byte[] b = new byte[buf.readableBytes()];
        //把数据从bytebuf转移到byte[]
        buf.getBytes(0, b);
        //将byte[]转成字符串用于打印
        return new String(b);
    }
}