第一个netty4的例子
这个例子参与http://netty.io/wiki/user-guide-for-4.x.html文档实现，主要是服务器接收并打印命令行输入的字符,例子简单直接上代码：
import io.netty.bootstrap.ServerBootstrap;import io.netty.buffer.ByteBuf;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.ChannelInboundHandlerAdapter;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;import io.netty.util.ReferenceCountUtil;public class DemoServer1 {public static void main(String[] args) throws InterruptedException {ServerBootstrap bootstrap = new ServerBootstrap();EventLoopGroup bossGroup = new NioEventLoopGroup(1); // (1) EventLoopGroup workerGroup = new NioEventLoopGroup(1); try{ bootstrap.group(bossGroup, workerGroup); bootstrap.channel(NioServerSocketChannel.class); bootstrap.childHandler(new ChannelInitializer<SocketChannel>(){@Overrideprotected void initChannel(SocketChannel ch) throws Exception {ch.pipeline().addLast(new MyHandler());} }); bootstrap.option(ChannelOption.SO_BACKLOG, 128); bootstrap.childOption(ChannelOption.SO_KEEPALIVE, true); ChannelFuture cfuture = bootstrap.bind(8080).sync(); cfuture.channel().closeFuture().sync(); }finally{ workerGroup.shutdownGracefully(); bossGroup.shutdownGracefully(); } }}class MyHandler extends ChannelInboundHandlerAdapter {private int index = 1;@Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { cause.printStackTrace();ctx.close();}@Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg)throws Exception {//super.channelRead(ctx, msg); try { System.out.println(((ByteBuf)msg).readableBytes()); // System.out.println(((ByteBuf)msg).toString()); System.out.println( ((ByteBuf)msg).toString(io.netty.util.CharsetUtil.US_ASCII)); System.out.println( ((ByteBuf)msg).toString(io.netty.util.CharsetUtil.US_ASCII)); //ctx.write(msg); //ctx.flush(); } finally { ReferenceCountUtil.release(msg); }}@Overridepublic void channelActive(ChannelHandlerContext ctx) throws Exception {super.channelActive(ctx);}}???? 服务启动后，直接使用telnet就可以和服务进行通信。?
??? 后边的章节写一下Netty4怎么实现整个NIO通信过程。
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