Netty+WebSocket簡單實現訊息推送
阿新 • • 發佈:2019-01-27
依賴
<dependencies>
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.25.Final</version>
</dependency>
</dependencies>
server
package com.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; public class WSServer { public static void main(String[] args) throws Exception { EventLoopGroup mainGroup = new NioEventLoopGroup(); EventLoopGroup subGroup = new NioEventLoopGroup(); try { ServerBootstrap server = new ServerBootstrap(); server.group(mainGroup, subGroup) .channel(NioServerSocketChannel.class) .childHandler(new WSServerInitialzer()); ChannelFuture future = server.bind(8088).sync(); System.out.println("start....."); future.channel().closeFuture().sync(); } finally { mainGroup.shutdownGracefully(); subGroup.shutdownGracefully(); } } }
initializer
package com.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; public class WSServerInitialzer extends ChannelInitializer<SocketChannel> { @Override protected void initChannel(SocketChannel ch) throws Exception { ChannelPipeline pipeline = ch.pipeline(); // websocket 基於http協議,所以要有http編解碼器 pipeline.addLast(new HttpServerCodec()); // 對寫大資料流的支援 pipeline.addLast(new ChunkedWriteHandler()); // 對httpMessage進行聚合,聚合成FullHttpRequest或FullHttpResponse // 幾乎在netty中的程式設計,都會使用到此hanler pipeline.addLast(new HttpObjectAggregator(1024*64)); // ====================== 以上是用於支援http協議 ====================== // ====================== 以下是支援httpWebsocket ====================== /** * websocket 伺服器處理的協議,用於指定給客戶端連線訪問的路由 : /ws * 本handler會幫你處理一些繁重的複雜的事 * 會幫你處理握手動作: handshaking(close, ping, pong) ping + pong = 心跳 * 對於websocket來講,都是以frames進行傳輸的,不同的資料型別對應的frames也不同 */ pipeline.addLast(new WebSocketServerProtocolHandler("/ws")); // 自定義的handler pipeline.addLast(new ChatHandler()); } }
handler
package com.netty.websocket; import java.time.LocalDateTime; 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; /** * * @Description: 處理訊息的handler * TextWebSocketFrame: 在netty中,是用於為websocket專門處理文字的物件,frame是訊息的載體 */ public class ChatHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> { // 用於記錄和管理所有客戶端的channle private static ChannelGroup clients = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE); @Override protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception { // 獲取客戶端傳輸過來的訊息 String content = msg.text(); System.out.println("接受到的資料:" + content); for (Channel channel: clients) { channel.writeAndFlush( new TextWebSocketFrame( "[伺服器在]" + LocalDateTime.now() + "接受到訊息, 訊息為:" + content)); } // 下面這個方法,和上面的for迴圈,一致 /*clients.writeAndFlush( new TextWebSocketFrame( "[伺服器在]" + LocalDateTime.now() + "接受到訊息, 訊息為:" + content));*/ } /** * 當客戶端連線服務端之後(開啟連線) * 獲取客戶端的channle,並且放到ChannelGroup中去進行管理 */ @Override public void handlerAdded(ChannelHandlerContext ctx) throws Exception { clients.add(ctx.channel()); } @Override public void handlerRemoved(ChannelHandlerContext ctx) throws Exception { // 當觸發handlerRemoved,ChannelGroup會自動移除對應客戶端的channel // clients.remove(ctx.channel()); System.out.println("客戶端斷開,channle對應的長id為:" + ctx.channel().id().asLongText()); System.out.println("客戶端斷開,channle對應的短id為:" + ctx.channel().id().asShortText()); } }
html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
</head>
<body>
<div>傳送訊息:</div>
<input type="text" id="msgContent" />
<input type="button" value="點我傳送" onclick="CHAT.chat()" />
<div>接受訊息:</div>
<div id="receiveMsg" style="background-color: gainsboro;"></div>
<script type="application/javascript">
window.CHAT = {
socket: null,
init: function() {
if(window.WebSocket) {
CHAT.socket = new WebSocket("ws://localhost:8088/ws");
CHAT.socket.onopen = function() {
console.log("連線建立成功...");
},
CHAT.socket.onclose = function() {
console.log("連線關閉...");
},
CHAT.socket.onerror = function() {
console.log("發生錯誤...");
},
CHAT.socket.onmessage = function(e) {
console.log("接受到訊息:" + e.data);
var receiveMsg = document.getElementById("receiveMsg");
var html = receiveMsg.innerHTML;
receiveMsg.innerHTML = html + "<br/>" + e.data;
}
} else {
alert("瀏覽器不支援websocket協議...");
}
},
chat: function() {
var msg = document.getElementById("msgContent");
CHAT.socket.send(msg.value);
document.getElementById("msgContent").value = '';
}
};
CHAT.init();
</script>
</body>
</html>
測試