Java tutorial
/* * Copyright 2013-2018 Lilinfeng. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.lampard.netty4.protocol.websocket.server; import static io.netty.handler.codec.http.HttpHeaders.isKeepAlive; import static io.netty.handler.codec.http.HttpHeaders.setContentLength; import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST; import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.codec.http.DefaultFullHttpResponse; import io.netty.handler.codec.http.FullHttpRequest; import io.netty.handler.codec.http.FullHttpResponse; import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame; import io.netty.handler.codec.http.websocketx.PingWebSocketFrame; import io.netty.handler.codec.http.websocketx.PongWebSocketFrame; import io.netty.handler.codec.http.websocketx.TextWebSocketFrame; import io.netty.handler.codec.http.websocketx.WebSocketFrame; import io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker; import io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory; import io.netty.util.CharsetUtil; import java.util.logging.Level; import java.util.logging.Logger; /** * @author lilinfeng * @date 2014214 * @version 1.0 */ public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> { private static final Logger logger = Logger.getLogger(WebSocketServerHandler.class.getName()); private WebSocketServerHandshaker handshaker; @Override public void messageReceived(ChannelHandlerContext ctx, Object msg) throws Exception { // HTTP if (msg instanceof FullHttpRequest) { handleHttpRequest(ctx, (FullHttpRequest) msg); } // WebSocket else if (msg instanceof WebSocketFrame) { handleWebSocketFrame(ctx, (WebSocketFrame) msg); } } @Override public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { ctx.flush(); } private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) throws Exception { // HTTP?HHTP if (!req.getDecoderResult().isSuccess() || (!"websocket".equals(req.headers().get("Upgrade")))) { sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST)); return; } // ?? WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory( "ws://localhost:8080/websocket", null, false); handshaker = wsFactory.newHandshaker(req); if (handshaker == null) { WebSocketServerHandshakerFactory.sendUnsupportedWebSocketVersionResponse(ctx.channel()); } else { handshaker.handshake(ctx.channel(), req); } } private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) { // ? if (frame instanceof CloseWebSocketFrame) { handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain()); return; } // ?Ping? if (frame instanceof PingWebSocketFrame) { ctx.channel().write(new PongWebSocketFrame(frame.content().retain())); return; } // ????? if (!(frame instanceof TextWebSocketFrame)) { throw new UnsupportedOperationException( String.format("%s frame types not supported", frame.getClass().getName())); } // ? String request = ((TextWebSocketFrame) frame).text(); if (logger.isLoggable(Level.FINE)) { logger.fine(String.format("%s received %s", ctx.channel(), request)); } ctx.channel().write(new TextWebSocketFrame(request + " , Netty WebSocket?" + new java.util.Date().toString())); } private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) { // if (res.getStatus().code() != 200) { ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8); res.content().writeBytes(buf); buf.release(); setContentLength(res, res.content().readableBytes()); } // ?Keep-Alive ChannelFuture f = ctx.channel().writeAndFlush(res); if (!isKeepAlive(req) || res.getStatus().code() != 200) { f.addListener(ChannelFutureListener.CLOSE); } } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { cause.printStackTrace(); ctx.close(); } }