1.DelimiterBasedFrameDecoder：是以分隔符作为结束标志进行解决粘包/拆包问题
代码：
EchoClient：客户端
/* * Copyright 2012 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package nettyTcp01.echo; 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.ChannelOption; 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 EchoClient { public void connect(int port, String host) throws Exception { // 配置客户端NIO线程组 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 { ByteBuf delimiter = Unpooled.copiedBuffer("$_".getBytes()); ch.pipeline().addLast(new DelimiterBasedFrameDecoder(1024, delimiter)); ch.pipeline().addLast(new StringDecoder()); ch.pipeline().addLast(new EchoClientHandler()); } }); // 发起异步连接操作 ChannelFuture f = b.connect(host, port).sync(); // 当代客户端链路关闭 f.channel().closeFuture().sync(); } finally { // 优雅退出，释放NIO线程组 group.shutdownGracefully(); } } /** * @param args * @throws Exception */ public static void main(String[] args) throws Exception { int port = 8080; String host = "127.0.0.1"; if (args != null && args.length > 0) { try { port = Integer.valueOf(args[0]); } catch (NumberFormatException e) { // 采用默认值 } } new EchoClient().connect(port, host); } }
EchoClientHandler：客户端数据处理
/* * Copyright 2012 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package nettyTcp01.echo; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; public class EchoClientHandler extends ChannelHandlerAdapter { private int counter; static final String ECHO_REQ = "Hi, Lilinfeng. Welcome to Netty.$_"; /** * Creates a client-side handler. */ public EchoClientHandler() { } @Override public void channelActive(ChannelHandlerContext ctx) { // ByteBuf buf = UnpooledByteBufAllocator.DEFAULT.buffer(ECHO_REQ // .getBytes().length); // buf.writeBytes(ECHO_REQ.getBytes()); for (int i = 0; i < 10; i++) { ctx.writeAndFlush(Unpooled.copiedBuffer(ECHO_REQ.getBytes())); } } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { String requestBody = (String) msg; System.out.println("This is " + ++counter + " times receive server : [" + requestBody + "]"); } @Override public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { ctx.flush(); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { cause.printStackTrace(); ctx.close(); } }
EchoServer：服务器端
/* * Copyright 2012 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package nettyTcp01.echo; import io.netty.bootstrap.ServerBootstrap; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; 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; import io.netty.handler.codec.DelimiterBasedFrameDecoder; import io.netty.handler.codec.string.StringDecoder; import io.netty.handler.logging.LogLevel; import io.netty.handler.logging.LoggingHandler; public class EchoServer { public void bind(int port) throws Exception { // 配置服务端的NIO线程组 EventLoopGroup bossGroup = new NioEventLoopGroup(); EventLoopGroup workerGroup = new NioEventLoopGroup(); try { ServerBootstrap b = new ServerBootstrap(); b.group(bossGroup, workerGroup) .channel(NioServerSocketChannel.class) .option(ChannelOption.SO_BACKLOG, 100) .handler(new LoggingHandler(LogLevel.INFO)) .childHandler(new ChannelInitializer<SocketChannel>() { @Override public void initChannel(SocketChannel ch) throws Exception { ByteBuf delimiter = Unpooled.copiedBuffer("$_".getBytes()); ch.pipeline().addLast(new DelimiterBasedFrameDecoder(1024,delimiter)); ch.pipeline().addLast(new StringDecoder()); ch.pipeline().addLast(new EchoServerHandler()); } }); // 绑定端口，同步等待成功 ChannelFuture f = b.bind(port).sync(); // 等待服务端监听端口关闭 f.channel().closeFuture().sync(); } finally { // 优雅退出，释放线程池资源 bossGroup.shutdownGracefully(); workerGroup.shutdownGracefully(); } } public static void main(String[] args) throws Exception { int port = 8080; if (args != null && args.length > 0) { try { port = Integer.valueOf(args[0]); } catch (NumberFormatException e) { // 采用默认值 } } new EchoServer().bind(port); } }
EchoServerHandler：服务器数据处理
/* * Copyright 2012 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package nettyTcp01.echo; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandler.Sharable; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; @Sharable public class EchoServerHandler extends ChannelHandlerAdapter { int counter = 0; @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { String responseBody = (String) msg; System.out.println("This is " + ++counter + " times receive client : ["+ responseBody + "]"); responseBody += "$_"; ByteBuf echo = Unpooled.copiedBuffer(responseBody.getBytes()); ctx.writeAndFlush(echo); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { cause.printStackTrace(); ctx.close();// 发生异常，关闭链路 } }