利用netty简单实现聊天室

 ???????<dependency> ???????????<groupId>io.netty</groupId> ???????????<artifactId>netty-all</artifactId> ???????????<version>5.0.0.Alpha1</version> ???????</dependency>

public class NettyServer { ???public static void main(String[] args) { ????????EventLoopGroup bossGroup = new NioEventLoopGroup(); ????????EventLoopGroup workGroup = new NioEventLoopGroup(); ????????ServerBootstrap bootStrap = new ServerBootstrap(); ???????????ChannelFuture cf; ???????????bootStrap.group(bossGroup,workGroup) ???????????????????.channel(NioServerSocketChannel.class) ???????????????????.option(ChannelOption.SO_BACKLOG, 1024) ???????????????????.childHandler(new ChannelInitializer<SocketChannel>() { ???????????????????????@Override ???????????????????????public void initChannel(SocketChannel ch) throws Exception { ???????????????????????????ChannelPipeline p = ch.pipeline(); ???????????????????????????p.addLast("decoder", new StringDecoder());//需要编解码，否则无法解析 ???????????????????????????p.addLast("encoder", new StringEncoder()); ???????????????????????????p.addLast(new NettyServerHandler()); ???????????????????????} ???????????????????}); ???????????try { ???????????????cf = ?bootStrap.bind(8099).sync();//监听8099端口 ???????????????System.out.println("8099:binded..."); ???????????????cf.channel().closeFuture().sync(); ???????????} catch (InterruptedException e) { ???????????????e.printStackTrace(); ???????????}finally{ ???????????????bossGroup.shutdownGracefully(); ???????????????workGroup.shutdownGracefully(); ???????????} ???}}

public class NettyClient { ???public static void main(String[] args) throws Exception { ???????EventLoopGroup group =new NioEventLoopGroup(); ???????try { ???????????Bootstrap b = new Bootstrap(); ???????????b.group(group) ???????????????????.channel(NioSocketChannel.class) ???????????????????.option(ChannelOption.TCP_NODELAY, true) ???????????????????.handler(new ChannelInitializer<SocketChannel>(){ ???????????????????????@Override ???????????????????????public void initChannel(SocketChannel ch) throws Exception { ???????????????????????????ChannelPipeline p = ch.pipeline(); ???????????????????????????p.addLast("decoder", new StringDecoder()); ???????????????????????????p.addLast("encoder", new StringEncoder()); ???????????????????????????p.addLast(new ClientHandler()); ???????????????????????????p.addLast(new ClientHandlerBak()); ???????????????????????} ???????????????????}); ???????????ChannelFuture future = b.connect("127.0.0.1", 8099).sync(); ???????????future.channel().writeAndFlush("这里是客户端，请求连接服务端！"); ???????????future.channel().closeFuture().sync(); ???????} finally { ???????????group.shutdownGracefully(); ???????} ???}}

public class NettyServerHandler extends ChannelHandlerAdapter { ???//有客户端连接时触发 ???@Override ???public void channelActive(ChannelHandlerContext ctx) throws Exception { ???????System.out.println("one client connect..."); ???} ???//断开连接时触发 ???@Override ???public void channelInactive(ChannelHandlerContext ctx) throws Exception { ???????System.out.println("one client disconnect..."); ???} ???//接收客户端发送的消息 ???@Override ???public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { ???????System.out.println("客户端："+msg.toString()); ???????InputStreamReader is = new InputStreamReader(System.in); ???????BufferedReader br = new BufferedReader(is); ???????String result ="result"; ???????try{ ???????????result = br.readLine(); ???????} ???????catch(IOException e){ ???????????e.printStackTrace(); ???????} ???????ctx.write(result);//给客户端回复 ???????ctx.flush(); ???}}

public class ClientHandler extends ChannelHandlerAdapter { ???@Override ???public void channelActive(ChannelHandlerContext ctx) throws Exception { ???????System.out.println("Client01Handler Active"); ???????/*若把这一句注释掉将无法将event传递给下一个ClientHandler,例如例子中p.addLast(new Client01Handler())后面紧跟着p.addLast(new Client02Handler()) ????????后面的Client02Handler里的方法就不会被触发。 ???????*/ ???????ctx.fireChannelActive(); ???} ???@Override ???public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { ???????System.out.println("服务端: "+msg); ???????InputStreamReader is = new InputStreamReader(System.in); ???????BufferedReader br = new BufferedReader(is); ???????String result ="result"; ???????try{ ???????????result = br.readLine(); ???????} ???????catch(IOException e){ ???????????e.printStackTrace(); ???????} ???????ctx.write(result);//给服务端回复 ???????ctx.flush(); ???} ???@Override ???public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { ???????cause.printStackTrace(); ???????ctx.close(); ???}}