netty权威指南学习笔记二——netty入门应用

　　经过了前面的NIO基础知识准备，我们已经对NIO有了较大了解，现在就进入netty的实际应用中来看看吧。重点体会整个过程。

按照权威指南写程序的过程中，发现一些问题：当我们在定义handler继承ChannelHanderAdapter时候，发现在其接口中没有可以实现的channelRead方法和channelReadComplete方法,然后查阅官网才发现netty5.0不见了，网上说是舍弃了，然后再看官网的一些例子，发现官网上继承的是ChannelInboundHandlerAdapter,当我将代码中handler的继承类更改为这个的时候发现前面的方法可以实现了。（同时发现ByteBuffer的一些方法调用不能调出书上的方法如readableBytes(),这个是我弄错了，ByteBuffer是jdk的包装类不是netty的，netty的应该用ByteBuf）为此将netty版本变更为

一、首先我们需要一个netty的环境，netty的环境搭建只需要一个netty的jar包即可。

　　在maven工程中导入netty的jar资源

 <dependency>
             <groupId>io.netty</groupId>
             <artifactId>netty-all</artifactId>
             <!--<version>5.0.0.Alpha1</version>-->
             <version>4.1.25.Final</version>
         </dependency>

二、netty 服务端代码

TimeServer

 package com.netty.example;

 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 TimeServer {
     public void bind(int port){
 //        创建接收任务的线程组和处理IO事件的线程组
         EventLoopGroup boosGroup = new NioEventLoopGroup();
         EventLoopGroup workGroup = new NioEventLoopGroup();
         try {
             ServerBootstrap bs = new ServerBootstrap();
             bs.group(boosGroup,workGroup)
                     .channel(NioServerSocketChannel.class)
                     .option(ChannelOption.SO_BACKLOG,1024)
                     .childHandler(new ChildChannelHandler());
 //        绑定端口号，同步等待成功
             ChannelFuture f = bs.bind(port).sync();
 //        等待服务器监听端口关闭
             f.channel().closeFuture().sync();
         } catch (InterruptedException e) {
             e.printStackTrace();
         }finally {
 //          优雅退出释放线程池资源
             boosGroup.shutdownGracefully();
             workGroup.shutdownGracefully();
         }
     }
     public static void main(String[] args){
         int port = 8080;
         if(args!=null&&args.length>0){
             port = Integer.valueOf(args[0]);
         }
         new TimeServer().bind(port);
     }

 private  class ChildChannelHandler extends ChannelInitializer<SocketChannel>{
     @Override
     protected void initChannel(SocketChannel socketChannel) throws Exception {
         socketChannel.pipeline().addLast(new TimeServerHandler());
     }

 }

 }

TimeServerHandler

 package com.netty.example;

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

 import java.util.Date;

 public class TimeServerHandler extends ChannelInboundHandlerAdapter {

     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
         ByteBuf buf = (ByteBuf) msg;//将接收到的msg转换为netty的BytyBuf对象，注意区分jdk中的ByteBuffer
         byte[] req = new byte[buf.readableBytes()];//创建接收缓冲区数据的字节数组
         buf.readBytes(req);//将缓冲区的数据读取到字节数组中
         String body = new String(req,"utf-8");//获取请求消息
         System.out.println("The time server receive order:"+body);
         String currentTime = "QUERY TIME ORDER".equalsIgnoreCase(body)?new Date(System.currentTimeMillis()).toString():"BAD ORDER";
         ByteBuf resp = Unpooled.copiedBuffer(currentTime.getBytes());//将响应信息封装为netty 的ByteBuf对象，
         ctx.write(resp);//异步发送应答消息给客户端
     }

     @Override
     public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
         /*将消息发送队列中的消息写道SocketChannel中发送给对方。从性能上考虑，为了防止频繁唤醒Selector进行消息发送
         * netty的write方法并不直接将消息写入socketChannel中，调用write方法只是把待发送的消息发送到数据缓冲数组中，
         * 再通过调用flush()方法，将发送缓冲区中的消息全部写道SocketChannel中*/
         ctx.flush();
     }

     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
         ctx.close();//发生异常时，关闭ChannelHandlerContext,释放ChannelHandlerContext相关联的句柄资源
     }
 }

三、netty 客户端代码

TimeClient

 package com.netty.example;

 import io.netty.bootstrap.Bootstrap;
 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;

 /*
 * 客户端代码
 * */
 public class TimeClient {
 //    配置客户端NIO线程
     public void connection(String host,int port) {
         EventLoopGroup group = new NioEventLoopGroup();
         try {
         Bootstrap bootstrap = new Bootstrap();
         bootstrap.group(group)
                 .channel(NioSocketChannel.class)
                 .option(ChannelOption.TCP_NODELAY,true)
                 .handler(new ChannelInitializer<SocketChannel>() {
                     @Override
                     protected void initChannel(SocketChannel socketChannel) throws Exception {
                         socketChannel.pipeline().addLast(new TimeClientHandler());
                     }
                 });
 //        发起异步连接操作
         ChannelFuture f = bootstrap.connect(host,port).sync();
 //        等待客户端链路关闭
             f.channel().closeFuture().sync();
         } catch (InterruptedException e) {
             e.printStackTrace();
         }finally{
             group.shutdownGracefully();
         }

     }
     public static void main(String[] args){
         int port = 8080;
         if(args.length>0&&args!=null){
            port = Integer.valueOf(args[0]);
         }
         new TimeClient().connection("127.0.0.1",port);
     }
 }

TimeClientHandler

 package com.netty.example;

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

 public class TimeClientHandler extends ChannelInboundHandlerAdapter {
     private final ByteBuf firstMsg;

     public TimeClientHandler() {
         byte[] req = "QUERY TIME ORDER".getBytes();
         firstMsg = Unpooled.buffer(req.length);
         firstMsg.writeBytes(req);
     }

     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {
     /*    当客户端和服务端TCP链路建立成功之后，Netty的NIO线程会调用channelActive方法，发送查询时间的指令给服务端，
         调用ChannelHandlerContext的writeAndFlush方法将请求消息发送给服务端
            当服务端返回应答消息时，channelRead()方法被调用*/
         ctx.writeAndFlush(firstMsg);
     }

     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
         ByteBuf buf = (ByteBuf) msg;
         byte[] req = new byte[buf.readableBytes()];
         buf.readBytes(req);
         String body = new String(req,"utf-8");
         System.out.println("Now is"+body);
     }

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

四、启动运行

开启服务端

 D:\java\java1.8\jdk1.8\bin\java.exe "-javaagent:D:\我的软件\itSoft\IntelliJ IDEA\IntelliJ IDEA 2018.1.5\lib\idea_rt.jar=59255:D:\我的软件\itSoft\IntelliJ IDEA\IntelliJ IDEA 2018.1.5\bin" -Dfile.encoding=UTF-8 -classpath 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rs\litan\.m2\repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.9.6\jackson-module-parameter-names-2.9.6.jar;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot-starter-tomcat\2.0.3.RELEASE\spring-boot-starter-tomcat-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\org\apache\tomcat\embed\tomcat-embed-core\8.5.31\tomcat-embed-core-8.5.31.jar;C:\Users\litan\.m2\repository\org\apache\tomcat\embed\tomcat-embed-el\8.5.31\tomcat-embed-el-8.5.31.jar;C:\Users\litan\.m2\repository\org\apache\tomcat\embed\tomcat-embed-websocket\8.5.31\tomcat-embed-websocket-8.5.31.jar;C:\Users\litan\.m2\repository\org\hibernate\validator\hibernate-validator\6.0.10.Final\hibernate-validator-6.0.10.Final.jar;C:\Users\litan\.m2\repository\javax\validation\validation-api\2.0.1.Final\validation-api-2.0.1.Final.jar;C:\Users\litan\.m2\repository\org\jboss\logging\jboss-logging\3.3.2.Final\jboss-logging-3.3.2.Final.jar;C:\Users\litan\.m2\repository\com\fasterxml\classmate\1.3.4\classmate-1.3.4.jar;C:\Users\litan\.m2\repository\org\springframework\spring-web\5.0.7.RELEASE\spring-web-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-beans\5.0.7.RELEASE\spring-beans-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-webmvc\5.0.7.RELEASE\spring-webmvc-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-context\5.0.7.RELEASE\spring-context-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-expression\5.0.7.RELEASE\spring-expression-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\mysql\mysql-connector-java\5.1.46\mysql-connector-java-5.1.46.jar;C:\Users\litan\.m2\repository\org\springframework\spring-core\5.0.7.RELEASE\spring-core-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-jcl\5.0.7.RELEASE\spring-jcl-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\io\netty\netty-all\4.1.25.Final\netty-all-4.1.25.Final.jar com.netty.example.TimeServer
 22:06:36.427 [main] DEBUG io.netty.util.internal.logging.InternalLoggerFactory - Using SLF4J as the default logging framework
 22:06:36.462 [main] DEBUG io.netty.channel.MultithreadEventLoopGroup - -Dio.netty.eventLoopThreads: 8
 22:06:36.509 [main] DEBUG io.netty.channel.nio.NioEventLoop - -Dio.netty.noKeySetOptimization: false
 22:06:36.509 [main] DEBUG io.netty.channel.nio.NioEventLoop - -Dio.netty.selectorAutoRebuildThreshold: 512
 22:06:36.556 [main] DEBUG io.netty.util.internal.PlatformDependent - Platform: Windows
 22:06:36.562 [main] DEBUG io.netty.util.internal.PlatformDependent0 - -Dio.netty.noUnsafe: false
 22:06:36.563 [main] DEBUG io.netty.util.internal.PlatformDependent0 - Java version: 8
 22:06:36.567 [main] DEBUG io.netty.util.internal.PlatformDependent0 - sun.misc.Unsafe.theUnsafe: available
 22:06:36.568 [main] DEBUG io.netty.util.internal.PlatformDependent0 - sun.misc.Unsafe.copyMemory: available
 22:06:36.569 [main] DEBUG io.netty.util.internal.PlatformDependent0 - java.nio.Buffer.address: available
 22:06:36.570 [main] DEBUG io.netty.util.internal.PlatformDependent0 - direct buffer constructor: available
 22:06:36.571 [main] DEBUG io.netty.util.internal.PlatformDependent0 - java.nio.Bits.unaligned: available, true
 22:06:36.571 [main] DEBUG io.netty.util.internal.PlatformDependent0 - jdk.internal.misc.Unsafe.allocateUninitializedArray(int): unavailable prior to Java9
 22:06:36.571 [main] DEBUG io.netty.util.internal.PlatformDependent0 - java.nio.DirectByteBuffer.<init>(long, int): available
 22:06:36.571 [main] DEBUG io.netty.util.internal.PlatformDependent - sun.misc.Unsafe: available
 22:06:36.573 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.tmpdir: C:\Users\litan\AppData\Local\Temp (java.io.tmpdir)
 22:06:36.575 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.bitMode: 64 (sun.arch.data.model)
 22:06:36.577 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.noPreferDirect: false
 22:06:36.577 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.maxDirectMemory: 1890582528 bytes
 22:06:36.577 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.uninitializedArrayAllocationThreshold: -1
 22:06:36.581 [main] DEBUG io.netty.util.internal.CleanerJava6 - java.nio.ByteBuffer.cleaner(): available
 22:06:36.595 [main] DEBUG io.netty.util.internal.PlatformDependent - org.jctools-core.MpscChunkedArrayQueue: available
 22:06:37.179 [main] DEBUG io.netty.channel.DefaultChannelId - -Dio.netty.processId: 14124 (auto-detected)
 22:06:37.186 [main] DEBUG io.netty.util.NetUtil - -Djava.net.preferIPv4Stack: false
 22:06:37.186 [main] DEBUG io.netty.util.NetUtil - -Djava.net.preferIPv6Addresses: false
 22:06:37.538 [main] DEBUG io.netty.util.NetUtil - Loopback interface: lo (Software Loopback Interface 1, 127.0.0.1)
 22:06:37.540 [main] DEBUG io.netty.util.NetUtil - Failed to get SOMAXCONN from sysctl and file \proc\sys\net\core\somaxconn. Default: 200
 22:06:38.027 [main] DEBUG io.netty.channel.DefaultChannelId - -Dio.netty.machineId: 00:50:56:ff:fe:c0:00:01 (auto-detected)
 22:06:38.038 [main] DEBUG io.netty.util.internal.InternalThreadLocalMap - -Dio.netty.threadLocalMap.stringBuilder.initialSize: 1024
 22:06:38.038 [main] DEBUG io.netty.util.internal.InternalThreadLocalMap - -Dio.netty.threadLocalMap.stringBuilder.maxSize: 4096
 22:06:38.090 [main] DEBUG io.netty.util.ResourceLeakDetector - -Dio.netty.leakDetection.level: simple
 22:06:38.091 [main] DEBUG io.netty.util.ResourceLeakDetector - -Dio.netty.leakDetection.targetRecords: 4
 22:06:38.144 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.numHeapArenas: 8
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.numDirectArenas: 8
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.pageSize: 8192
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.maxOrder: 11
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.chunkSize: 16777216
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.tinyCacheSize: 512
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.smallCacheSize: 256
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.normalCacheSize: 64
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.maxCachedBufferCapacity: 32768
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.cacheTrimInterval: 8192
 22:06:38.145 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.useCacheForAllThreads: true
 22:06:38.159 [main] DEBUG io.netty.buffer.ByteBufUtil - -Dio.netty.allocator.type: pooled
 22:06:38.159 [main] DEBUG io.netty.buffer.ByteBufUtil - -Dio.netty.threadLocalDirectBufferSize: 0
 22:06:38.159 [main] DEBUG io.netty.buffer.ByteBufUtil - -Dio.netty.maxThreadLocalCharBufferSize: 16384

客户端运行后

 D:\java\java1.8\jdk1.8\bin\java.exe "-javaagent:D:\我的软件\itSoft\IntelliJ IDEA\IntelliJ IDEA 2018.1.5\lib\idea_rt.jar=59302:D:\我的软件\itSoft\IntelliJ IDEA\IntelliJ IDEA 2018.1.5\bin" -Dfile.encoding=UTF-8 -classpath D:\java\java1.8\jdk1.8\jre\lib\charsets.jar;D:\java\java1.8\jdk1.8\jre\lib\deploy.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\access-bridge-64.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\cldrdata.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\dnsns.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\jaccess.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\jfxrt.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\localedata.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\nashorn.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\sunec.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\sunjce_provider.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\sunmscapi.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\sunpkcs11.jar;D:\java\java1.8\jdk1.8\jre\lib\ext\zipfs.jar;D:\java\java1.8\jdk1.8\jre\lib\javaws.jar;D:\java\java1.8\jdk1.8\jre\lib\jce.jar;D:\java\java1.8\jdk1.8\jre\lib\jfr.jar;D:\java\java1.8\jdk1.8\jre\lib\jfxswt.jar;D:\java\java1.8\jdk1.8\jre\lib\jsse.jar;D:\java\java1.8\jdk1.8\jre\lib\management-agent.jar;D:\java\java1.8\jdk1.8\jre\lib\plugin.jar;D:\java\java1.8\jdk1.8\jre\lib\resources.jar;D:\java\java1.8\jdk1.8\jre\lib\rt.jar;D:\netty\target\classes;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot-starter-data-redis\2.0.3.RELEASE\spring-boot-starter-data-redis-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot-starter\2.0.3.RELEASE\spring-boot-starter-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot\2.0.3.RELEASE\spring-boot-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot-autoconfigure\2.0.3.RELEASE\spring-boot-autoconfigure-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot-starter-logging\2.0.3.RELEASE\spring-boot-starter-logging-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;C:\Users\litan\.m2\repository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;C:\Users\litan\.m2\repository\org\apache\logging\log4j\log4j-to-slf4j\2.10.0\log4j-to-slf4j-2.10.0.jar;C:\Users\litan\.m2\repository\org\apache\logging\log4j\log4j-api\2.10.0\log4j-api-2.10.0.jar;C:\Users\litan\.m2\repository\org\slf4j\jul-to-slf4j\1.7.25\jul-to-slf4j-1.7.25.jar;C:\Users\litan\.m2\repository\javax\annotation\javax.annotation-api\1.3.2\javax.annotation-api-1.3.2.jar;C:\Users\litan\.m2\repository\org\yaml\snakeyaml\1.19\snakeyaml-1.19.jar;C:\Users\litan\.m2\repository\org\springframework\data\spring-data-redis\2.0.8.RELEASE\spring-data-redis-2.0.8.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\data\spring-data-keyvalue\2.0.8.RELEASE\spring-data-keyvalue-2.0.8.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\data\spring-data-commons\2.0.8.RELEASE\spring-data-commons-2.0.8.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-tx\5.0.7.RELEASE\spring-tx-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-oxm\5.0.7.RELEASE\spring-oxm-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-aop\5.0.7.RELEASE\spring-aop-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-context-support\5.0.7.RELEASE\spring-context-support-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\slf4j\slf4j-api\1.7.25\slf4j-api-1.7.25.jar;C:\Users\litan\.m2\repository\io\lettuce\lettuce-core\5.0.4.RELEASE\lettuce-core-5.0.4.RELEASE.jar;C:\Users\litan\.m2\repository\io\projectreactor\reactor-core\3.1.8.RELEASE\reactor-core-3.1.8.RELEASE.jar;C:\Users\litan\.m2\repository\org\reactivestreams\reactive-streams\1.0.2\reactive-streams-1.0.2.jar;C:\Users\litan\.m2\repository\io\netty\netty-common\4.1.25.Final\netty-common-4.1.25.Final.jar;C:\Users\litan\.m2\repository\io\netty\netty-transport\4.1.25.Final\netty-transport-4.1.25.Final.jar;C:\Users\litan\.m2\repository\io\netty\netty-buffer\4.1.25.Final\netty-buffer-4.1.25.Final.jar;C:\Users\litan\.m2\repository\io\netty\netty-resolver\4.1.25.Final\netty-resolver-4.1.25.Final.jar;C:\Users\litan\.m2\repository\io\netty\netty-handler\4.1.25.Final\netty-handler-4.1.25.Final.jar;C:\Users\litan\.m2\repository\io\netty\netty-codec\4.1.25.Final\netty-codec-4.1.25.Final.jar;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot-starter-web\2.0.3.RELEASE\spring-boot-starter-web-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot-starter-json\2.0.3.RELEASE\spring-boot-starter-json-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\com\fasterxml\jackson\core\jackson-databind\2.9.6\jackson-databind-2.9.6.jar;C:\Users\litan\.m2\repository\com\fasterxml\jackson\core\jackson-annotations\2.9.0\jackson-annotations-2.9.0.jar;C:\Users\litan\.m2\repository\com\fasterxml\jackson\core\jackson-core\2.9.6\jackson-core-2.9.6.jar;C:\Users\litan\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.9.6\jackson-datatype-jdk8-2.9.6.jar;C:\Users\litan\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.9.6\jackson-datatype-jsr310-2.9.6.jar;C:\Users\litan\.m2\repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.9.6\jackson-module-parameter-names-2.9.6.jar;C:\Users\litan\.m2\repository\org\springframework\boot\spring-boot-starter-tomcat\2.0.3.RELEASE\spring-boot-starter-tomcat-2.0.3.RELEASE.jar;C:\Users\litan\.m2\repository\org\apache\tomcat\embed\tomcat-embed-core\8.5.31\tomcat-embed-core-8.5.31.jar;C:\Users\litan\.m2\repository\org\apache\tomcat\embed\tomcat-embed-el\8.5.31\tomcat-embed-el-8.5.31.jar;C:\Users\litan\.m2\repository\org\apache\tomcat\embed\tomcat-embed-websocket\8.5.31\tomcat-embed-websocket-8.5.31.jar;C:\Users\litan\.m2\repository\org\hibernate\validator\hibernate-validator\6.0.10.Final\hibernate-validator-6.0.10.Final.jar;C:\Users\litan\.m2\repository\javax\validation\validation-api\2.0.1.Final\validation-api-2.0.1.Final.jar;C:\Users\litan\.m2\repository\org\jboss\logging\jboss-logging\3.3.2.Final\jboss-logging-3.3.2.Final.jar;C:\Users\litan\.m2\repository\com\fasterxml\classmate\1.3.4\classmate-1.3.4.jar;C:\Users\litan\.m2\repository\org\springframework\spring-web\5.0.7.RELEASE\spring-web-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-beans\5.0.7.RELEASE\spring-beans-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-webmvc\5.0.7.RELEASE\spring-webmvc-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-context\5.0.7.RELEASE\spring-context-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-expression\5.0.7.RELEASE\spring-expression-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\mysql\mysql-connector-java\5.1.46\mysql-connector-java-5.1.46.jar;C:\Users\litan\.m2\repository\org\springframework\spring-core\5.0.7.RELEASE\spring-core-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\org\springframework\spring-jcl\5.0.7.RELEASE\spring-jcl-5.0.7.RELEASE.jar;C:\Users\litan\.m2\repository\io\netty\netty-all\4.1.25.Final\netty-all-4.1.25.Final.jar com.netty.example.TimeClient
 22:07:35.228 [main] DEBUG io.netty.util.internal.logging.InternalLoggerFactory - Using SLF4J as the default logging framework
 22:07:35.273 [main] DEBUG io.netty.channel.MultithreadEventLoopGroup - -Dio.netty.eventLoopThreads: 8
 22:07:35.329 [main] DEBUG io.netty.channel.nio.NioEventLoop - -Dio.netty.noKeySetOptimization: false
 22:07:35.329 [main] DEBUG io.netty.channel.nio.NioEventLoop - -Dio.netty.selectorAutoRebuildThreshold: 512
 22:07:35.387 [main] DEBUG io.netty.util.internal.PlatformDependent - Platform: Windows
 22:07:35.390 [main] DEBUG io.netty.util.internal.PlatformDependent0 - -Dio.netty.noUnsafe: false
 22:07:35.390 [main] DEBUG io.netty.util.internal.PlatformDependent0 - Java version: 8
 22:07:35.393 [main] DEBUG io.netty.util.internal.PlatformDependent0 - sun.misc.Unsafe.theUnsafe: available
 22:07:35.394 [main] DEBUG io.netty.util.internal.PlatformDependent0 - sun.misc.Unsafe.copyMemory: available
 22:07:35.395 [main] DEBUG io.netty.util.internal.PlatformDependent0 - java.nio.Buffer.address: available
 22:07:35.396 [main] DEBUG io.netty.util.internal.PlatformDependent0 - direct buffer constructor: available
 22:07:35.397 [main] DEBUG io.netty.util.internal.PlatformDependent0 - java.nio.Bits.unaligned: available, true
 22:07:35.397 [main] DEBUG io.netty.util.internal.PlatformDependent0 - jdk.internal.misc.Unsafe.allocateUninitializedArray(int): unavailable prior to Java9
 22:07:35.397 [main] DEBUG io.netty.util.internal.PlatformDependent0 - java.nio.DirectByteBuffer.<init>(long, int): available
 22:07:35.397 [main] DEBUG io.netty.util.internal.PlatformDependent - sun.misc.Unsafe: available
 22:07:35.398 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.tmpdir: C:\Users\litan\AppData\Local\Temp (java.io.tmpdir)
 22:07:35.398 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.bitMode: 64 (sun.arch.data.model)
 22:07:35.400 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.noPreferDirect: false
 22:07:35.400 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.maxDirectMemory: 1890582528 bytes
 22:07:35.400 [main] DEBUG io.netty.util.internal.PlatformDependent - -Dio.netty.uninitializedArrayAllocationThreshold: -1
 22:07:35.401 [main] DEBUG io.netty.util.internal.CleanerJava6 - java.nio.ByteBuffer.cleaner(): available
 22:07:35.420 [main] DEBUG io.netty.util.internal.PlatformDependent - org.jctools-core.MpscChunkedArrayQueue: available
 22:07:36.030 [main] DEBUG io.netty.channel.DefaultChannelId - -Dio.netty.processId: 18472 (auto-detected)
 22:07:36.032 [main] DEBUG io.netty.util.NetUtil - -Djava.net.preferIPv4Stack: false
 22:07:36.033 [main] DEBUG io.netty.util.NetUtil - -Djava.net.preferIPv6Addresses: false
 22:07:36.324 [main] DEBUG io.netty.util.NetUtil - Loopback interface: lo (Software Loopback Interface 1, 127.0.0.1)
 22:07:36.325 [main] DEBUG io.netty.util.NetUtil - Failed to get SOMAXCONN from sysctl and file \proc\sys\net\core\somaxconn. Default: 200
 22:07:36.895 [main] DEBUG io.netty.channel.DefaultChannelId - -Dio.netty.machineId: 00:50:56:ff:fe:c0:00:01 (auto-detected)
 22:07:36.905 [main] DEBUG io.netty.util.internal.InternalThreadLocalMap - -Dio.netty.threadLocalMap.stringBuilder.initialSize: 1024
 22:07:36.905 [main] DEBUG io.netty.util.internal.InternalThreadLocalMap - -Dio.netty.threadLocalMap.stringBuilder.maxSize: 4096
 22:07:36.938 [main] DEBUG io.netty.util.ResourceLeakDetector - -Dio.netty.leakDetection.level: simple
 22:07:36.938 [main] DEBUG io.netty.util.ResourceLeakDetector - -Dio.netty.leakDetection.targetRecords: 4
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.numHeapArenas: 8
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.numDirectArenas: 8
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.pageSize: 8192
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.maxOrder: 11
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.chunkSize: 16777216
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.tinyCacheSize: 512
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.smallCacheSize: 256
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.normalCacheSize: 64
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.maxCachedBufferCapacity: 32768
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.cacheTrimInterval: 8192
 22:07:36.992 [main] DEBUG io.netty.buffer.PooledByteBufAllocator - -Dio.netty.allocator.useCacheForAllThreads: true
 22:07:37.029 [main] DEBUG io.netty.buffer.ByteBufUtil - -Dio.netty.allocator.type: pooled
 22:07:37.029 [main] DEBUG io.netty.buffer.ByteBufUtil - -Dio.netty.threadLocalDirectBufferSize: 0
 22:07:37.029 [main] DEBUG io.netty.buffer.ByteBufUtil - -Dio.netty.maxThreadLocalCharBufferSize: 16384
 22:07:37.080 [nioEventLoopGroup-2-1] DEBUG io.netty.buffer.AbstractByteBuf - -Dio.netty.buffer.bytebuf.checkAccessible: true
 22:07:37.084 [nioEventLoopGroup-2-1] DEBUG io.netty.util.ResourceLeakDetectorFactory - Loaded default ResourceLeakDetector: io.netty.util.ResourceLeakDetector@75655d17
 22:07:37.126 [nioEventLoopGroup-2-1] DEBUG io.netty.util.Recycler - -Dio.netty.recycler.maxCapacityPerThread: 4096
 22:07:37.126 [nioEventLoopGroup-2-1] DEBUG io.netty.util.Recycler - -Dio.netty.recycler.maxSharedCapacityFactor: 2
 22:07:37.126 [nioEventLoopGroup-2-1] DEBUG io.netty.util.Recycler - -Dio.netty.recycler.linkCapacity: 16
 22:07:37.126 [nioEventLoopGroup-2-1] DEBUG io.netty.util.Recycler - -Dio.netty.recycler.ratio: 8
 Now isMon Jul 16 22:07:37 CST 2018

上面客户端最后一行是收到的服务端的应答，此时的服务端也出现了收到消息的语句，最后部分代码如下（重点是最后一行的请求消息）：

 22:06:38.159 [main] DEBUG io.netty.buffer.ByteBufUtil - -Dio.netty.maxThreadLocalCharBufferSize: 16384
 22:07:37.160 [nioEventLoopGroup-3-1] DEBUG io.netty.util.Recycler - -Dio.netty.recycler.maxCapacityPerThread: 4096
 22:07:37.160 [nioEventLoopGroup-3-1] DEBUG io.netty.util.Recycler - -Dio.netty.recycler.maxSharedCapacityFactor: 2
 22:07:37.160 [nioEventLoopGroup-3-1] DEBUG io.netty.util.Recycler - -Dio.netty.recycler.linkCapacity: 16
 22:07:37.160 [nioEventLoopGroup-3-1] DEBUG io.netty.util.Recycler - -Dio.netty.recycler.ratio: 8
 22:07:37.176 [nioEventLoopGroup-3-1] DEBUG io.netty.buffer.AbstractByteBuf - -Dio.netty.buffer.bytebuf.checkAccessible: true
 22:07:37.179 [nioEventLoopGroup-3-1] DEBUG io.netty.util.ResourceLeakDetectorFactory - Loaded default ResourceLeakDetector: io.netty.util.ResourceLeakDetector@164ea267
 The time server receive order:QUERY TIME ORDER

运行OK！