以前经常用netty来写TCP链接的处理,然后有些需求就是要求数据实时更新,所以就想到了websocket。
netty实现websockt跟TCP区别不大,主要区别就是配置的解码器和添加关于websocket的东西,业务处理并没有特殊添加。
简单实现
首先引入netty依赖
<dependencies>
<!-- https://mvnrepository.com/artifact/io.netty/netty-all -->
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.36.Final</version>
</dependency>
</dependencies>
配置NettyServer
package com.home.reptile.netty;
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;
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;
/**
* @author wqy
* @version 1.0
* @date 2019/8/8 15:39
*/
public class NettyServer {
private final int port;
public NettyServer(int port){
this.port = port;
}
public void start() throws Exception{
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup group = new NioEventLoopGroup();
try {
ServerBootstrap sb = new ServerBootstrap();
sb.option(ChannelOption.SO_BACKLOG,1024);
sb.group(group,bossGroup)//绑定线程池
.channel(NioServerSocketChannel.class)//指定使用的channel
.localAddress(this.port)//绑定监听端口
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
System.out.println("收到新连接");
//websocket协议本身就是基于http协议的,所以这边也要使用http编解码器
ch.pipeline().addLast(new HttpServerCodec());
//以块的方式来写处理器
ch.pipeline().addLast(new ChunkedWriteHandler());
ch.pipeline().addLast(new HttpObjectAggregator(8192));
ch.pipeline().addLast(new WebSocketServerProtocolHandler("/ws",null,true,65536*10));
ch.pipeline().addLast(new MyWebSocketHandler());
}
});
//服务器异步创建绑定
ChannelFuture cf = sb.bind().sync();
System.out.println(NettyServer.class+" 启动正在监听: "+cf.channel().localAddress());
//关闭服务器通道
cf.channel().closeFuture().sync();
} finally {
group.shutdownGracefully().sync();
bossGroup.shutdownGracefully().sync();
}
}
}
启动nettyserver,开启一个线程,单独启动server
package com.home.reptile.netty;
/**
* @author wqy
* @version 1.0
* @date 2019/8/8 16:06
*/
public class StratNetty implements Runnable{
@Override
public void run() {
try {
new NettyServer(6655).start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
处理业务逻辑和通道管理
package com.home.reptile.netty;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import java.util.HashMap;
import java.util.Map;
/**
* @author wqy
* @version 1.0
* @date 2019/8/8 15:59
*/
public class MyWebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
/**
* 通道建立调用
* @param ctx
* @throws Exception
*/
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
System.out.println("与客户端建立连接,通道开启!");
//将链接存入连接池(自定义)
MyChannelHandlerPool.channelGroup.add(ctx.channel());
}
/**
* 通道断开调用
* @param ctx
* @throws Exception
*/
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
System.out.println("与客户端断开连接,通道关闭!");
//添加到channelGroup 通道组
MyChannelHandlerPool.channelGroup.remove(ctx.channel());
}
/**
* 通道数据读取
* @param ctx
* @param msg
* @throws Exception
*/
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
//首次连接是FullHttpRequest,处理参数 by zhengkai.blog.youkuaiyun.com
if (null != msg && msg instanceof FullHttpRequest) {
FullHttpRequest request = (FullHttpRequest) msg;
String uri = request.uri();
Map paramMap=getUrlParams(uri);
//System.out.println("接收到的参数是:"+JSON.toJSONString(paramMap));
//如果url包含参数,需要处理
if(uri.contains("?")){
String newUri=uri.substring(0,uri.indexOf("?"));
System.out.println(newUri);
request.setUri(newUri);
}
}else if(msg instanceof TextWebSocketFrame){
//正常的TEXT消息类型
TextWebSocketFrame frame=(TextWebSocketFrame)msg;
System.out.println("客户端收到服务器数据:" +frame.text());
sendAllMessage(frame.text());
}
super.channelRead(ctx, msg);
}
@Override
protected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame textWebSocketFrame) throws Exception {
}
private void sendAllMessage(String message){
//收到信息后,群发给所有channel
MyChannelHandlerPool.channelGroup.writeAndFlush( new TextWebSocketFrame(message));
}
private static Map getUrlParams(String url){
Map<String,String> map = new HashMap<>();
url = url.replace("?",";");
if (!url.contains(";")){
return map;
}
if (url.split(";").length > 0){
String[] arr = url.split(";")[1].split("&");
for (String s : arr){
String key = s.split("=")[0];
String value = s.split("=")[1];
map.put(key,value);
}
return map;
}else{
return map;
}
}
}
通道连接池
package com.home.reptile.netty;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.util.concurrent.GlobalEventExecutor;
/**
* @author wqy
* @version 1.0
* @date 2019/8/8 15:59
*/
public class MyChannelHandlerPool {
public MyChannelHandlerPool(){}
public static ChannelGroup channelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
}
页面
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Netty-Websocket</title>
<script type="text/javascript">
// by zhengkai.blog.youkuaiyun.com
var socket;
if(!window.WebSocket){
window.WebSocket = window.MozWebSocket;
}
if(window.WebSocket){
socket = new WebSocket("ws://127.0.0.1:6655/ws");
socket.onmessage = function(event){
var ta = document.getElementById('responseText');
ta.value += event.data+"\r\n";
};
socket.onopen = function(event){
var ta = document.getElementById('responseText');
ta.value = "Netty-WebSocket服务器。。。。。。连接 \r\n";
};
socket.onclose = function(event){
var ta = document.getElementById('responseText');
ta.value = "Netty-WebSocket服务器。。。。。。关闭 \r\n";
};
}else{
alert("您的浏览器不支持WebSocket协议!");
}
function send(message){
if(!window.WebSocket){return;}
if(socket.readyState == WebSocket.OPEN){
socket.send(message);
}else{
alert("WebSocket 连接没有建立成功!");
}
}
</script>
</head>
<body>
<form onSubmit="return false;">
<label>ID</label><input type="text" name="uid" value="${uid!!}" /> <br />
<label>TEXT</label><input type="text" name="message" value="这里输入消息" /> <br />
<br /> <input type="button" value="发送ws消息"
onClick="send(this.form.uid.value+':'+this.form.message.value)" />
<hr color="black" />
<h3>服务端返回的应答消息</h3>
<textarea id="responseText" style="width: 1024px;height: 300px;"></textarea>
</form>
</body>
</html>
controller
@RestController
public class IndexController {
@GetMapping("/index")
public ModelAndView index(){
ModelAndView mav=new ModelAndView("socket");
mav.addObject("uid", RandomUtil.randomNumbers(6));
return mav;
}
}
差不多一个简单的例子就实现了
积少成多。