netty群聊系统
实例要求
1) 编写一个 Netty 群聊系统,实现服务器端和客户端之间的数据简单通讯(非阻塞)
2) 实现多人群聊
3) 服务器端:可以监测用户上线,离线,并实现消息转发功能
4) 客户端:通过 channel 可以无阻塞发送消息给其它所有用户,同时可以接受其它用户发送的消息(有服务器转发
得到)
服务端
1、GroupChatServer
package com.atguigu.netty.groupchat; import io.netty.bootstrap.ServerBootstrap; import io.netty.channel.*; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.SocketChannel; import io.netty.channel.socket.nio.NioServerSocketChannel; import io.netty.handler.codec.string.StringDecoder; import io.netty.handler.codec.string.StringEncoder; public class GroupChatServer { private int port; //监听端口 public GroupChatServer(int port) { this.port = port; } //编写run方法,处理客户端的请求 public void run() throws Exception{ //创建两个线程组 EventLoopGroup bossGroup = new NioEventLoopGroup(1); EventLoopGroup workerGroup = new NioEventLoopGroup(); //8个NioEventLoop try { ServerBootstrap b = new ServerBootstrap(); b.group(bossGroup, workerGroup) //异步的服务器端 TCP Socket 连接 .channel(NioServerSocketChannel.class) //用来给 ServerChannel 添加配置 //SO_BACKLOG对应TCP/IP协议listen函数中的backlog参数,用来初始化服务器可连接队列大小。 .option(ChannelOption.SO_BACKLOG, 128) //用来给接收到的通道添加配置 //SO_KEEPALIVE,一直保持连接活动状态 .childOption(ChannelOption.SO_KEEPALIVE, true) //该方法用来设置业务处理类(自定义的 handler) .childHandler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { //获取到pipeline ChannelPipeline pipeline = ch.pipeline(); //向pipeline加入解码器 pipeline.addLast("decoder", new StringDecoder()); //向pipeline加入编码器 pipeline.addLast("encoder", new StringEncoder()); //加入自己的业务处理handler pipeline.addLast(new GroupChatServerHandler()); } }); System.out.println("netty 服务器启动"); //该方法用于服务器端,用来设置占用的端口号。等待异步操作执行完毕 ChannelFuture channelFuture = b.bind(port).sync(); //监听关闭 channelFuture.channel().closeFuture().sync(); }finally { bossGroup.shutdownGracefully(); workerGroup.shutdownGracefully(); } } public static void main(String[] args) throws Exception { new GroupChatServer(7000).run(); } }
2、GroupChatServerHandler
package com.atguigu.netty.groupchat; import io.netty.channel.Channel; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.channel.group.ChannelGroup; import io.netty.channel.group.DefaultChannelGroup; import io.netty.util.concurrent.GlobalEventExecutor; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; public class GroupChatServerHandler extends SimpleChannelInboundHandler<String> { //public static List<Channel> channels = new ArrayList<Channel>(); //使用一个hashmap 管理 //public static Map<String, Channel> channels = new HashMap<String,Channel>(); //定义一个channle 组,管理所有的channel //GlobalEventExecutor.INSTANCE) 是全局的事件执行器,是一个单例 private static ChannelGroup channelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //handlerAdded 表示连接建立,一旦连接,第一个被执行 //将当前channel 加入到 channelGroup @Override public void handlerAdded(ChannelHandlerContext ctx) throws Exception { Channel channel = ctx.channel(); //将该客户加入聊天的信息推送给其它在线的客户端 /* 该方法会将 channelGroup 中所有的channel 遍历,并发送 消息, 我们不需要自己遍历 */ channelGroup.writeAndFlush("[客户端]" + channel.remoteAddress() + " 加入聊天" + sdf.format(new java.util.Date()) + " \n"); channelGroup.add(channel); } //断开连接, 将xx客户离开信息推送给当前在线的客户 @Override public void handlerRemoved(ChannelHandlerContext ctx) throws Exception { Channel channel = ctx.channel(); channelGroup.writeAndFlush("[客户端]" + channel.remoteAddress() + " 离开了\n"); System.out.println("channelGroup size" + channelGroup.size()); } //表示channel 处于活动状态, 提示 xx上线 @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { System.out.println(ctx.channel().remoteAddress() + " 上线了~"); } //表示channel 处于不活动状态, 提示 xx离线了 @Override public void channelInactive(ChannelHandlerContext ctx) throws Exception { System.out.println(ctx.channel().remoteAddress() + " 离线了~"); } //读取数据 @Override protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception { //获取到当前channel Channel channel = ctx.channel(); //这时我们遍历channelGroup, 根据不同的情况,回送不同的消息 channelGroup.forEach(ch -> { if(channel != ch) { //不是当前的channel,转发消息 ch.writeAndFlush("[客户]" + channel.remoteAddress() + " 发送了消息" + msg + "\n"); }else {//回显自己发送的消息给自己 ch.writeAndFlush("[自己]发送了消息" + msg + "\n"); } }); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { //关闭通道 ctx.close(); } }
客户端
1、GroupChatClient
package com.atguigu.netty.groupchat; import io.netty.bootstrap.Bootstrap; import io.netty.channel.*; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.SocketChannel; import io.netty.channel.socket.nio.NioSocketChannel; import io.netty.handler.codec.string.StringDecoder; import io.netty.handler.codec.string.StringEncoder; import java.util.Scanner; public class GroupChatClient { //属性 private final String host; private final int port; public GroupChatClient(String host, int port) { this.host = host; this.port = port; } public void run() throws Exception{ EventLoopGroup group = new NioEventLoopGroup(); try { Bootstrap bootstrap = new Bootstrap() .group(group) .channel(NioSocketChannel.class) .handler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { //得到pipeline ChannelPipeline pipeline = ch.pipeline(); //加入相关handler pipeline.addLast("decoder", new StringDecoder()); pipeline.addLast("encoder", new StringEncoder()); //加入自定义的handler pipeline.addLast(new GroupChatClientHandler()); } }); ChannelFuture channelFuture = bootstrap.connect(host, port).sync(); //得到channel Channel channel = channelFuture.channel(); System.out.println("-------" + channel.localAddress()+ "--------"); //客户端需要输入信息,创建一个扫描器 Scanner scanner = new Scanner(System.in); while (scanner.hasNextLine()) { String msg = scanner.nextLine(); //通过channel 发送到服务器端 channel.writeAndFlush(msg + "\r\n"); } }finally { group.shutdownGracefully(); } } public static void main(String[] args) throws Exception { new GroupChatClient("127.0.0.1", 7000).run(); } }
2、GroupChatClientHandler
package com.atguigu.netty.groupchat; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; public class GroupChatClientHandler extends SimpleChannelInboundHandler<String> { @Override protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception { System.out.println(msg.trim()); } }
运行效果
netty心跳检测应用
实例要求
1) 编写一个 Netty 心跳检测机制案例, 当服务器超过 3 秒没有读时,就提示读空闲
2) 当服务器超过 5 秒没有写操作时,就提示写空闲
3) 实现当服务器超过 7 秒没有读或者写操作时,就提示读写空闲
服务端
1、MyServer
package com.atguigu.netty.heartbeat; import io.netty.bootstrap.ServerBootstrap; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelInitializer; 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.NioServerSocketChannel; import io.netty.handler.logging.LogLevel; import io.netty.handler.logging.LoggingHandler; import io.netty.handler.timeout.IdleStateHandler; import java.util.concurrent.TimeUnit; public class MyServer { public static void main(String[] args) throws Exception{ //创建两个线程组 EventLoopGroup bossGroup = new NioEventLoopGroup(1); EventLoopGroup workerGroup = new NioEventLoopGroup(); //8个NioEventLoop try { ServerBootstrap serverBootstrap = new ServerBootstrap(); serverBootstrap.group(bossGroup, workerGroup); serverBootstrap.channel(NioServerSocketChannel.class); serverBootstrap.handler(new LoggingHandler(LogLevel.INFO)); serverBootstrap.childHandler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { ChannelPipeline pipeline = ch.pipeline(); //加入一个netty 提供 IdleStateHandler /* 说明 1. IdleStateHandler 是netty 提供的处理空闲状态的处理器 2. long readerIdleTime : 表示多长时间没有读, 就会发送一个心跳检测包检测是否连接 3. long writerIdleTime : 表示多长时间没有写, 就会发送一个心跳检测包检测是否连接 4. long allIdleTime : 表示多长时间没有读写, 就会发送一个心跳检测包检测是否连接 5. 文档说明 triggers an {@link IdleStateEvent} when a {@link Channel} has not performed * read, write, or both operation for a while. * 6. 当 IdleStateEvent 触发后 , 就会传递给管道 的下一个handler去处理 * 通过调用(触发)下一个handler 的 userEventTiggered , 在该方法中去处理 IdleStateEvent(读空闲,写空闲,读写空闲) */ pipeline.addLast(new IdleStateHandler(7000,7000,10, TimeUnit.SECONDS)); //加入一个对空闲检测进一步处理的handler(自定义) pipeline.addLast(new MyServerHandler()); } }); //启动服务器 ChannelFuture channelFuture = serverBootstrap.bind(7000).sync(); channelFuture.channel().closeFuture().sync(); }finally { bossGroup.shutdownGracefully(); workerGroup.shutdownGracefully(); } } }
2、MyServerHandler
package com.atguigu.netty.heartbeat; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInboundHandlerAdapter; import io.netty.handler.timeout.IdleStateEvent; public class MyServerHandler extends ChannelInboundHandlerAdapter { /** * * @param ctx 上下文 * @param evt 事件 * @throws Exception */ @Override public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception { if(evt instanceof IdleStateEvent) { //将 evt 向下转型 IdleStateEvent IdleStateEvent event = (IdleStateEvent) evt; String eventType = null; switch (event.state()) { case READER_IDLE: eventType = "读空闲"; break; case WRITER_IDLE: eventType = "写空闲"; break; case ALL_IDLE: eventType = "读写空闲"; break; } System.out.println(ctx.channel().remoteAddress() + "--超时时间--" + eventType); System.out.println("服务器做相应处理.."); //如果发生空闲,我们关闭通道 // ctx.channel().close(); } } }
通过SSL/TLS 保护Netty 应用程序代码实战
目的
实现一个简单的支持https的服务端以及客户端
代码
服务端
1、HttpServer
package cn.enjoyedu.server;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel; import io.netty.handler.ssl.SslContext; import io.netty.handler.ssl.SslContextBuilder; import io.netty.handler.ssl.util.SelfSignedCertificate; public class HttpServer { public static final int port = 6789; //设置服务端端口 private static EventLoopGroup group = new NioEventLoopGroup(); private static ServerBootstrap b = new ServerBootstrap(); private static final boolean SSL = false; public static void main(String[] args) throws Exception { final SslContext sslCtx; if (SSL) { //netty为我们提供的ssl加密,缺省 SelfSignedCertificate ssc = new SelfSignedCertificate(); sslCtx = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey()).build(); } else { sslCtx = null; } try { b.group(group); b.channel(NioServerSocketChannel.class); b.childHandler(new ServerHandlerInit(sslCtx)); // 服务器绑定端口监听 ChannelFuture f = b.bind(port).sync(); System.out.println("服务端启动成功,端口是:"+port); // 监听服务器关闭监听 f.channel().closeFuture().sync(); } finally { group.shutdownGracefully(); } } }
2、ServerHandlerInit
package cn.enjoyedu.server;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.HttpContentCompressor;
import io.netty.handler.codec.http.HttpObjectAggregator; import io.netty.handler.codec.http.HttpRequestDecoder; import io.netty.handler.codec.http.HttpResponseEncoder; import io.netty.handler.ssl.SslContext; public class ServerHandlerInit extends ChannelInitializer<SocketChannel> { private final SslContext sslCtx; public ServerHandlerInit(SslContext sslCtx) { this.sslCtx = sslCtx; } @Override protected void initChannel(SocketChannel ch) throws Exception { ChannelPipeline ph = ch.pipeline(); if (sslCtx != null) { ph.addLast(sslCtx.newHandler(ch.alloc())); } //http响应编码 ph.addLast("encode",new HttpResponseEncoder()); //http请求编码 ph.addLast("decode",new HttpRequestDecoder()); //聚合http请求 ph.addLast("aggre", new HttpObjectAggregator(10*1024*1024)); //启用http压缩 ph.addLast("compressor",new HttpContentCompressor()); //自己的业务处理 ph.addLast("busi",new BusiHandler()); } }
3、BusiHandler
package cn.enjoyedu.server;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.http.*; import io.netty.util.CharsetUtil; public class BusiHandler extends ChannelInboundHandlerAdapter { private String result=""; private void send(String content, ChannelHandlerContext ctx, HttpResponseStatus status){ FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1,status, Unpooled.copiedBuffer(content,CharsetUtil.UTF_8)); response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain;charset=UTF-8"); ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE); } /* * 收到消息时,返回信息 */ @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { String result=""; //接收到完成的http请求 FullHttpRequest httpRequest = (FullHttpRequest)msg; try{ String path = httpRequest.uri(); String body = httpRequest.content().toString(CharsetUtil.UTF_8); HttpMethod method = httpRequest.method(); if(!"/test".equalsIgnoreCase(path)){ result = "非法请求:"+path; send(result,ctx,HttpResponseStatus.BAD_REQUEST); return; } //处理http GET请求 if(HttpMethod.GET.equals(method)){ System.out.println("body:"+body); result="Get request,Response="+RespConstant.getNews(); send(result,ctx,HttpResponseStatus.OK); } //处理http POST请求 if(HttpMethod.POST.equals(method)){ //..... } }catch(Exception e){ System.out.println("处理请求失败!"); e.printStackTrace(); }finally{ httpRequest.release(); } } /* * 建立连接时,返回消息 */ @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { System.out.println("连接的客户端地址:" + ctx.channel().remoteAddress()); } }
4、RespConstant
package cn.enjoyedu.server;
import java.util.Random;
public class RespConstant {
private static final String[] NEWS = {
"她那时候还太年轻,不知道所有命运赠送的礼物,早已在暗中标好了" +
"价格。——斯蒂芬·茨威格《断头皇后》",
"这是一个最好的时代,也是一个最坏的时代;" +
"这是一个智慧的年代,这是一个愚蠢的年代;\n" +
"这是一个信任的时期,这是一个怀疑的时期;" +
"这是一个光明的季节,这是一个黑暗的季节;\n" +
"这是希望之春,这是失望之冬;" +
"人们面前应有尽有,人们面前一无所有;\n" +
"人们正踏上天堂之路,人们正走向地狱之门。 —— 狄更斯《双城记》", }; private static final Random R = new Random(); public static String getNews(){ return NEWS[R.nextInt(NEWS.length)]; } }
客户端
1、HttpClient
package cn.enjoyedu.client;
import cn.enjoyedu.server.HttpServer;
import io.netty.bootstrap.Bootstrap;
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.http.*; import java.net.URI; public class HttpClient { private static final boolean SSL = false; public void connect(String host, int port) throws Exception { EventLoopGroup workerGroup = new NioEventLoopGroup(); try { Bootstrap b = new Bootstrap(); b.group(workerGroup); b.channel(NioSocketChannel.class); b.option(ChannelOption.SO_KEEPALIVE, true); b.handler(new ChannelInitializer<SocketChannel>() { @Override public void initChannel(SocketChannel ch) throws Exception { ch.pipeline().addLast(new HttpClientCodec()); ch.pipeline().addLast("aggre", new HttpObjectAggregator(10*1024*1024)); ch.pipeline().addLast("decompressor",new HttpContentDecompressor()); ch.pipeline().addLast("busi",new HttpClientInboundHandler()); } }); // Start the client. ChannelFuture f = b.connect(host, port).sync(); URI uri = new URI("/test"); String msg = "Hello"; DefaultFullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, uri.toASCIIString(), Unpooled.wrappedBuffer(msg.getBytes("UTF-8"))); // 构建http请求 request.headers().set(HttpHeaderNames.HOST, host); request.headers() .set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE); request.headers() .set(HttpHeaderNames.CONTENT_LENGTH, request.content().readableBytes()); // 发送http请求 f.channel().write(request); f.channel().flush(); f.channel().closeFuture().sync(); } finally { workerGroup.shutdownGracefully(); } } public static void main(String[] args) throws Exception { HttpClient client = new HttpClient(); client.connect("127.0.0.1", HttpServer.port); } }
2、HttpClientInboundHandler
package cn.enjoyedu.client;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.util.CharsetUtil; public class HttpClientInboundHandler extends ChannelInboundHandlerAdapter { public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { //开始对服务器的响应做处理 FullHttpResponse httpResponse = (FullHttpResponse)msg; System.out.println(httpResponse.headers()); ByteBuf content = httpResponse.content(); System.out.println(content.toString(CharsetUtil.UTF_8)); content.release(); } }