3.Netty的粘包、拆包（二） (2)

日期：2021-04-30 栏目：程序人生浏览：次

（2）服务端ServerHandler

package com.xm.netty.demo03; import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import io.netty.util.CharsetUtil; public class ServerHandler extends ChannelHandlerAdapter { @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { String str = (String) msg; System.out.println("Server:"+str); str = "服务器返回--->"+ str+"$"; ctx.writeAndFlush(Unpooled.copiedBuffer(str.getBytes())); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { cause.printStackTrace(); ctx.close(); } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { System.out.println(DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(LocalDateTime.now())+"一个客户端连接上服务器！"); } }

（3）客户端Client

package com.xm.netty.demo03; import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; import io.netty.bootstrap.Bootstrap; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; 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; import io.netty.handler.codec.DelimiterBasedFrameDecoder; import io.netty.handler.codec.string.StringDecoder; public class Client { private final int port; private final String host; public Client(int port, String host) { this.port = port; this.host = host; } public static void main(String[] args) { String host = "127.0.0.1"; int port = 8989; try { new Client(port, host).start(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } private void start() throws InterruptedException { EventLoopGroup group = new NioEventLoopGroup(); try { Bootstrap bootstrap = new Bootstrap(); bootstrap .group(group) .channel(NioSocketChannel.class) .remoteAddress(host, port) .handler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { ByteBuf buf = Unpooled.copiedBuffer("$".getBytes()); ch.pipeline().addLast(new DelimiterBasedFrameDecoder(1024,buf)); ch.pipeline().addLast(new StringDecoder()); ch.pipeline().addLast(new ClientHandler()); } }); ChannelFuture future = bootstrap.connect().sync(); for(int i=10;i<20;i++) { String str = DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(LocalDateTime.now()) + "---- " +i+"<<<$"; future.channel().write(Unpooled.copiedBuffer(str.getBytes())); } future.channel().flush(); //future.channel().writeAndFlush(Unpooled.copiedBuffer("Hello Netty!".getBytes())); future.channel().closeFuture().sync(); } finally { group.shutdownGracefully().sync(); } } }

（4）客户端ClientHandler

package com.xm.netty.demo03; import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; import io.netty.util.CharsetUtil; import io.netty.util.ReferenceCountUtil; public class ClientHandler extends ChannelHandlerAdapter { @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { try { String str = (String) msg; System.out.println("Client:"+str); } finally { ReferenceCountUtil.release(msg); } } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { cause.printStackTrace(); ctx.close(); } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { System.out.println(DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(LocalDateTime.now())+"已连接服务器！"); } }

运行结果截图

（1）服务端运行结果：

3.Netty的粘包、拆包（二）