引入pom依赖
<!-- https://mvnrepository.com/artifact/io.netty/netty-all --> <dependency> <groupId>io.netty</groupId> <artifactId>netty-all</artifactId> <version>4.1.31.Final</version> </dependency>
Ajax轮询
Long pull
websocket
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; /** * @program: study_netty * @description: WebSocketServer * @author: Mr.superbeyone * @create: 2018-11-20 13:37 **/ public class WSServer { public static void main(String[] args) throws Exception{ // 定义主线程池 EventLoopGroup boss = new NioEventLoopGroup(); // 定义从线程池 EventLoopGroup work = new NioEventLoopGroup(); try { // 定义Server服务器 ServerBootstrap bootstrap = new ServerBootstrap(); bootstrap.group(boss, work) .channel(NioServerSocketChannel.class) .childHandler(new WSServerInitializer()); ChannelFuture channelFuture = bootstrap.bind(8888).sync(); channelFuture.channel().closeFuture().sync(); } finally { //优雅关闭 boss.shutdownGracefully(); work.shutdownGracefully(); } } }
import com.superbeyone.netty.websocket.handler.ChatHandler; import io.netty.channel.ChannelInitializer; import io.netty.channel.ChannelPipeline; import io.netty.channel.socket.SocketChannel; import io.netty.handler.codec.http.HttpObjectAggregator; import io.netty.handler.codec.http.HttpServerCodec; import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler; import io.netty.handler.stream.ChunkedWriteHandler; /** * @program: study_netty * @description: WebSocket初始化器 * @author: Mr.superbeyone * @create: 2018-11-20 13:44 **/ public class WSServerInitializer extends ChannelInitializer<SocketChannel> { @Override protected void initChannel(SocketChannel ch) throws Exception { ChannelPipeline pipeline = ch.pipeline(); // WebSocket是基于HTTP协议,所以要有HTTP编解码器 pipeline.addLast("HttpServerCodec", new HttpServerCodec()); // 提供对写大数据流的支持 pipeline.addLast("ChunkedWriteHandler", new ChunkedWriteHandler()); // 对HttpMessage进行聚合,聚合成FullHttpRequest或者FullHttpResponse 该handler使用率极高 pipeline.addLast(new HttpObjectAggregator(1024 * 64)); //1024 *64 为最大消息长度 //========================================以上用于支持HTTP协议=================================================== //======================================以下用于支持WebSocket协议================================================ /** * WebSocket 服务器处理的协议,用于指定给客户端连接访问的路由:/ws * 本handler会帮你处理一些繁重的复杂工作,比如:握手动作 handshaking (close,ping,pong) ping + pong = 心跳检测 * 对于WebSocket来讲,都是以frames进行传输的,不同的数据类型对应的frames也不同 */ pipeline.addLast(new WebSocketServerProtocolHandler("/ws")); // 添加自定义handler pipeline.addLast("ChatHandler", new ChatHandler()); } }
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.handler.codec.http.websocketx.TextWebSocketFrame; import io.netty.util.concurrent.GlobalEventExecutor; import java.time.LocalDateTime; /** * @program: study_netty * @description: 自定义处理消息的Handler * @author: Mr.superbeyone * @create: 2018-11-20 14:03 **/ /** * TextWebSocketFrame: 在Netty中,是用于为WebSocket专门处理文本的对象,frame是消息的载体 */ public class ChatHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> { // 用于管理和记录所有客户端的Channel private static ChannelGroup clients = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE); @Override protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception { // 获取从客户端传输过来的消息 String content = msg.text(); System.out.println("接收到的消息:\t" + content); for (Channel channel : clients) { channel.writeAndFlush(new TextWebSocketFrame("服务器在[" + LocalDateTime.now() + "]接收到消息,内容为:\t" + content)); } // 等价于for循环 // clients.writeAndFlush(new TextWebSocketFrame("[服务器在]" + LocalDateTime.now()+ "接收到消息,内容为" + content)); } /** * 当客户端连接服务端之后(打开连接) * 获取客户端的channel,并且放到ChannelGroup中进行管理 * * @param ctx * @throws Exception */ @Override public void handlerAdded(ChannelHandlerContext ctx) throws Exception { clients.add(ctx.channel()); } @Override public void handlerRemoved(ChannelHandlerContext ctx) throws Exception { // 当触发handlerRemoved,ChannelGroup会自动移除对应客户端的Channel // clients.remove(ctx.channel()); System.out.println("客户端断开,channel对应的长id为:\t" + ctx.channel().id().asLongText()); System.out.println("客户端断开,channel对应的短id为:\t" + ctx.channel().id().asShortText()); super.handlerRemoved(ctx); } }
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>WebSocket</title> </head> <body> 发送消息: <input type="text" id="msgContent"> <input type="button" onclick="CHAT.chat()" value="点我发送"> <br> <hr> 接收消息: <div id="receiveMsg" style="background-color: lightgray"></div> <script> window.CHAT = { socket: null, init: function () { //判断浏览器是否支持WebSocket if (window.WebSocket) { CHAT.socket = new WebSocket("ws://localhost:8888/ws"); CHAT.socket.onopen = function () { console.log("连接建立成功"); }, CHAT.socket.onclose = function () { console.log("连接关闭"); }, CHAT.socket.onerror = function () { console.log("发生错误"); }, CHAT.socket.onmessage = function (e) { console.log("接收到消息: " + e.data); var receiveMsg = document.getElementById("receiveMsg"); var html = receiveMsg.innerHTML; receiveMsg.innerHTML = html + "<br/>" + e.data; } } else { alert("浏览器不支持WebSocket协议"); } }, chat: function () { var msg = document.getElementById("msgContent"); CHAT.socket.send(msg.value); } } CHAT.init(); </script> </body> </html>