Java tutorial
/** * Copyright 2012 Ronen Hamias, Anton Kharenko * * 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 io.scalecube.socketio.pipeline; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.io.IOException; import java.util.UUID; import io.netty.buffer.ByteBuf; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandler; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInboundHandlerAdapter; import io.netty.handler.codec.http.DefaultHttpResponse; import io.netty.handler.codec.http.HttpMethod; import io.netty.handler.codec.http.HttpRequest; import io.netty.handler.codec.http.HttpResponse; import io.netty.handler.codec.http.HttpResponseStatus; import io.netty.handler.codec.http.QueryStringDecoder; import io.netty.util.ReferenceCountUtil; import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1; /** * This class implements Socket.IO handshake procedure described below: * * <h1>Handshake</h1> * * <p> * The client will perform an initial HTTP POST request like the following * </p> * * <p> * {@code http://example.com/socket.io/1/} * </p> * * <p> * The absence of the transport id and session id segments will signal the * server this is a new, non-handshaken connection. * </p> * * <p> * The server can respond in three different ways: * </p> * * <p> * {@code 401 Unauthorized} * </p> * * <p> * If the server refuses to authorize the client to connect, based on the * supplied information (eg: Cookie header or custom query components). * </p> * * <p> * No response body is required. * </p> * * <p> * {@code 503 Service Unavailable} * </p> * * <p> * If the server refuses the connection for any reason (eg: overload). * </p> * * <p> * No response body is required. * </p> * * <p> * {@code 200 OK} * </p> * * <p> * The handshake was successful. * </p> * * <p> * The body of the response should contain the session id (sid) given to the * client, followed by the heartbeat timeout, the connection closing timeout, * and the list of supported transports separated by {@code :} * </p> * * <p> * The absence of a heartbeat timeout ('') is interpreted as the server and * client not expecting heartbeats. * </p> * * <p> * For example {@code 4d4f185e96a7b:15:10:websocket,xhr-polling} * </p> * * @author Anton Kharenko, Ronen Hamias * */ @ChannelHandler.Sharable public class HandshakeHandler extends ChannelInboundHandlerAdapter { private final Logger log = LoggerFactory.getLogger(getClass()); private final String handshakePath; private final String commonHandshakeParameters; public HandshakeHandler(final String handshakePath, final int heartbeatTimeout, final int closeTimeout, final String transports) { this.handshakePath = handshakePath; commonHandshakeParameters = ":" + heartbeatTimeout + ":" + closeTimeout + ":" + transports; } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { // if (msg instanceof HttpRequest) { final HttpRequest req = (HttpRequest) msg; final HttpMethod requestMethod = req.getMethod(); final QueryStringDecoder queryDecoder = new QueryStringDecoder(req.getUri()); final String requestPath = queryDecoder.path(); if (!requestPath.startsWith(handshakePath)) { log.warn("Received HTTP bad request: {} {} from channel: {}", requestMethod, requestPath, ctx.channel()); HttpResponse res = new DefaultHttpResponse(HTTP_1_1, HttpResponseStatus.BAD_REQUEST); ChannelFuture f = ctx.channel().writeAndFlush(res); f.addListener(ChannelFutureListener.CLOSE); ReferenceCountUtil.release(req); return; } if (HttpMethod.GET.equals(requestMethod) && requestPath.equals(handshakePath)) { if (log.isDebugEnabled()) log.debug("Received HTTP handshake request: {} {} from channel: {}", requestMethod, requestPath, ctx.channel()); handshake(ctx, req, queryDecoder); ReferenceCountUtil.release(req); return; } } super.channelRead(ctx, msg); } private void handshake(final ChannelHandlerContext ctx, final HttpRequest req, final QueryStringDecoder queryDecoder) throws IOException { // Generate session ID final String sessionId = UUID.randomUUID().toString(); if (log.isDebugEnabled()) log.debug("New sessionId: {} generated", sessionId); // Send handshake response final String handshakeMessage = getHandshakeMessage(sessionId, queryDecoder); ByteBuf content = PipelineUtils.copiedBuffer(ctx.alloc(), handshakeMessage); HttpResponse res = PipelineUtils.createHttpResponse(PipelineUtils.getOrigin(req), content, false); ChannelFuture f = ctx.writeAndFlush(res); f.addListener(ChannelFutureListener.CLOSE); if (log.isDebugEnabled()) log.debug("Sent handshake response: {} to channel: {}", handshakeMessage, ctx.channel()); } private String getHandshakeMessage(final String sessionId, final QueryStringDecoder queryDecoder) throws IOException { String jsonpParam = PipelineUtils.extractParameter(queryDecoder, "jsonp"); String handshakeParameters = sessionId + commonHandshakeParameters; if (jsonpParam != null) { return "io.j[" + jsonpParam + "](\"" + handshakeParameters + "\");"; } else { return handshakeParameters; } } }