概述
websocket使用主从线程组模型,仅实现浏览器发送数据,服务器接收数据控制台输出并转发给所有连接的客户端
端口绑定8088
代码
主启动类 WSServer.java
package com.imooc.netty.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;
/**
* @Author Sakura
* @Date 5/8/2019
**/
public class WSServer {
public static void main(String[] args) throws Exception {
//创建主从线程组
EventLoopGroup mainGroup = new NioEventLoopGroup();
EventLoopGroup subGroup = new NioEventLoopGroup();
try {
ServerBootstrap serverBootstrap = new ServerBootstrap();
serverBootstrap.group(mainGroup,subGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new WSServerInitializer());
//绑定端口,同步启动
ChannelFuture channelFuture = serverBootstrap.bind(8088).sync();
//监听关闭,同步启动
channelFuture.channel().closeFuture().sync();
} finally {
mainGroup.shutdownGracefully();
subGroup.shutdownGracefully();
}
}
}
初始化器 WSServerInitializer.java
package com.imooc.netty.websocket;
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;
/**
* @Author Sakura
* @Date 5/8/2019
**/
public class WSServerInitializer extends ChannelInitializer<SocketChannel> {
protected void initChannel(SocketChannel socketChannel) throws Exception {
ChannelPipeline pipeline = socketChannel.pipeline();
//websoket基于http,所以有http编码解码器
pipeline.addLast(new HttpServerCodec());
//对写大数据流的支持
pipeline.addLast(new ChunkedWriteHandler());
//对httpMessage进行聚合,聚合成HttpRequest或HttpResponse
//几乎在Netty的编程都会使用到此handler
pipeline.addLast(new HttpObjectAggregator(1024*64));
//====================以上是用于支持Http协议===========================
/**
* websocket服务器处理协议,用于指定给客户端访问的路由:/ws (比如 ws://localhost:8088/ws)
* 本handler会处理以下繁重的事务
* 握手动作:handshaking(close,ping--请求,pong--响应)
* websocket都是以frames进行传输,不同数据类型frames也不同
*/
pipeline.addLast(new WebSocketServerProtocolHandler("/ws"));
//自定义通信助手类,客户端消息处理与消息回送
pipeline.addLast(new ChatHandler());
}
}
自定义助手类 ChatHandler.java
package com.imooc.netty.websocket;
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;
/**
* @Author Sakura
* @Date 5/8/2019
* 处理消息的handler
* TextWebSocketFrame 在netty中专门为websocket处理文本的对象,frame是消息载体
**/
public class ChatHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {
//用于记录和管理所有客户端channel的ChannelGroup
private static ChannelGroup clients = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
protected void channelRead0(ChannelHandlerContext channelHandlerContext, TextWebSocketFrame msg) throws Exception {
//获取客户端传输的消息
String content = msg.text();
System.out.println("接受到的数据为:" + content);
// for (Channel channel:clients) {
// channel.writeAndFlush(
// new TextWebSocketFrame("[服务器于"+ LocalDateTime.now()+ "收到消息]:" + content)
// );
// }
//该方法同以上循环
clients.writeAndFlush(new TextWebSocketFrame("[服务器于"+ LocalDateTime.now()+ "收到消息]:" + content));
}
/**
*客户端连接服务端后(打开链接)
* 获取客户端channel,并放入ChannelGroup中管理
*/
@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
clients.add(ctx.channel());
}
/**
* 当触发handlerRemoved方法时,ChannelGroup会自动移除对应客户端的channel
* 所以无需手动remove
*/
@Override
public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
//clients.remove(ctx.channel());
//每个channel都有标是自身的id,分长短。有大型channel时短id可能重复
System.out.println("客户端断开,channel对应长id为:"+ ctx.channel().id().asLongText());
System.out.println("客户端断开,channel对应短id为:"+ ctx.channel().id().asShortText());
}
}
前端代码
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
</head>
<body>
<text>消息发送</text> <br/>
<input type="text" id="msgSend" />
<input type="button" value="发送" onclick="CHAT.chat()"/><br/>
<text>消息接收</text><br/>
<div id="msgRecv" style="background-color: blanchedalmond;"></div>
<script type="text/javascript">
window.CHAT = {
socket:null,
init:function(){
if(window.WebSocket){
CHAT.socket = new WebSocket("ws://127.0.0.1:8088/ws");
CHAT.socket.onopen=function(){
console.log("建立连接");
},
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("收到消息:"+e.data)
var msgRecv = document.getElementById("msgRecv");
var html = msgRecv.innerHTML;
msgRecv.innerHTML = html + "<br/>" + e.data;
}
}else{
alert("该浏览器不支持websocket");
}
},
chat:function(){
var msg = document.getElementById("msgSend");
CHAT.socket.send(msg.value)
}
}
CHAT.init()
</script>
</body>
</html>
测试
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