菜鸟Java使用Netty

下载下来，搜索半天，如何使用Netty。。。。。。。。。。。网上找不到一篇类似的文章。对新手真是巨大的创伤啊！

还下载了Maven。现在还不知道这个东西干嘛的。好像对我使用Natty一点帮助都没有。

下载完，解压至某指定目录。

然后引入它的包即可

打开两个Eclipse

一个写一个服务器，一个写一个客户端 

服务器结果如下：

此四步用于引入Netty的包。

客户端亦如此

EchoServer.java 代码为：

/* * 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 netty.echo.handler;import io.netty.buffer.ByteBuf;import io.netty.buffer.Unpooled;import io.netty.channel.ChannelFutureListener;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.ChannelInboundHandlerAdapter;import io.netty.channel.ChannelHandler.Sharable;@Sharablepublic class EchoServerHandler extends ChannelInboundHandlerAdapter {@Overridepublic void channelActive(ChannelHandlerContext ctx) {System.out.println("channelActive!!!!!!!!!!!");}@Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg) {System.out.println("channelRead!!!!!!!!!!!!!!!!!!!!!!!");ByteBuf buf = (ByteBuf)msg;//System.out.println(buf.);ctx.write(msg);}@Overridepublic void channelReadComplete(ChannelHandlerContext ctx) {ctx.flush();}@Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {// Close the connection when an exception is raised.cause.printStackTrace();ctx.close();}}

EchoServerHandler.java 代码为：

/* * 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 netty.echo.handler;import io.netty.buffer.ByteBuf;import io.netty.buffer.Unpooled;import io.netty.channel.ChannelFutureListener;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.ChannelInboundHandlerAdapter;import io.netty.channel.ChannelHandler.Sharable;@Sharablepublic class EchoServerHandler extends ChannelInboundHandlerAdapter {@Overridepublic void channelActive(ChannelHandlerContext ctx) {System.out.println("channelActive!!!!!!!!!!!");}@Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg) {System.out.println("channelRead!!!!!!!!!!!!!!!!!!!!!!!");ByteBuf buf = (ByteBuf)msg;//System.out.println(buf.);ctx.write(msg);}@Overridepublic void channelReadComplete(ChannelHandlerContext ctx) {ctx.flush();}@Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {// Close the connection when an exception is raised.cause.printStackTrace();ctx.close();}}

             客户端               

EchoClient.java 代码为：

/* * 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 netty.echo.client;import io.netty.bootstrap.Bootstrap;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelOption;import io.netty.channel.ChannelPipeline;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.ssl.SslContext;import io.netty.handler.ssl.SslContextBuilder;import io.netty.handler.ssl.util.InsecureTrustManagerFactory;public final class EchoClient {static final boolean SSL = System.getProperty("ssl") != null;static final String HOST = System.getProperty("host", "127.0.0.1");static final int PORT = Integer.parseInt(System.getProperty("port", "8007"));static final int SIZE = Integer.parseInt(System.getProperty("size", "256"));public static void main(String[] args) throws Exception {// Configure SSL.gitfinal SslContext sslCtx = null;// Configure the client.EventLoopGroup group = new NioEventLoopGroup();try {Bootstrap b = new Bootstrap();b.group(group).channel(NioSocketChannel.class).option(ChannelOption.TCP_NODELAY, true).handler(new ChannelInitializer<SocketChannel>() {@Overridepublic void initChannel(SocketChannel ch) throws Exception {ChannelPipeline p = ch.pipeline();if (sslCtx != null) {p.addLast(sslCtx.newHandler(ch.alloc(), HOST, PORT));}// p.addLast(new LoggingHandler(LogLevel.INFO));p.addLast(new EchoClientHandler());}});// Start the client.ChannelFuture f = b.connect(HOST, PORT).sync();// Wait until the connection is closed.f.channel().closeFuture().sync();} finally {// Shut down the event loop to terminate all threads.group.shutdownGracefully();}}}

EchoClientHandler.java 代码为：

/* * 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 netty.echo.client;import io.netty.buffer.ByteBuf;import io.netty.buffer.Unpooled;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.ChannelInboundHandlerAdapter;/** * Handler implementation for the echo client.  It initiates the ping-pong * traffic between the echo client and server by sending the first message to * the server. */public class EchoClientHandler extends ChannelInboundHandlerAdapter {    private final ByteBuf firstMessage;    /**     * Creates a client-side handler.     */    public EchoClientHandler() {        firstMessage = Unpooled.buffer(EchoClient.SIZE);        for (int i = 0; i < firstMessage.capacity(); i ++) {            firstMessage.writeByte((byte) i);        }    }    @Override    public void channelActive(ChannelHandlerContext ctx) {        //ctx.writeAndFlush(firstMessage);    String x = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";    firstMessage.writeBytes(x.getBytes());    ctx.writeAndFlush(firstMessage);    }    @Override    public void channelRead(ChannelHandlerContext ctx, Object msg) {        ctx.write(msg);    }    @Override    public void channelReadComplete(ChannelHandlerContext ctx) {       ctx.flush();    }    @Override    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {        // Close the connection when an exception is raised.        cause.printStackTrace();        ctx.close();    }}

运行结果：

服务器启动为Java Application类型，

客户端启动后，服务器的反应：

http://blog.csdn.net/suifeng3051/article/details/25238243

     这里有一个形象的比喻来形容Netty客户端和服务器端的交互模式，

比如把你比作一个Client，把山比作一个Server，你走到山旁，就是和山建立了链接，

你向山大喊了一声，就代表向山发送了数据，你的喊声经过山的反射形成了回声，这个回声就是服务器的响应数据。如果你离开，就代表断开了链接，当然你也可以再回来。

好多人可以同时向山大喊，他们的喊声也一定会得到山的回应。

官方文档：

http://netty.io/wiki/user-guide-for-4.x.html#wiki-h3-17

Netty4.x中文教程系列(一) 目录及概述 - Tiny&zzh - 博客园

 http://www.cnblogs.com/zou90512/p/3492287.html

[Android初级]android与netty4初体验 - 消失的天空 - 博客频道 - CSDN.NET

 http://blog.csdn.net/jan_s/article/details/43702569

Netty4详解三：Netty架构设计 - Heaven Wang 的专栏 - 博客频道 - CSDN.NET  http://blog.csdn.net/suifeng3051/article/details/28861883?utm_source=tuicool&utm_medium=referral Netty4详解