Java tutorial
/* * Copyright 2015 the original author or authors. * * 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.heliosapm.tsdblite.handlers.websock; import static io.netty.handler.codec.http.HttpHeaderNames.HOST; import static io.netty.handler.codec.http.HttpMethod.GET; import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST; import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN; import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND; import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1; import java.io.PrintWriter; import java.io.StringWriter; import java.util.LinkedHashMap; import java.util.Map; import com.fasterxml.jackson.databind.JsonNode; import com.heliosapm.tsdblite.handlers.http.HttpRequestManager; import com.heliosapm.tsdblite.json.JSON; import com.heliosapm.utils.collections.FluentMap; import com.heliosapm.utils.collections.FluentMap.MapType; 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.HttpRequest; import io.netty.handler.codec.http.HttpUtil; 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 io.netty.util.internal.chmv8.ConcurrentHashMapV8; /** * <p>Title: WebSocketServerHandler</p> * <p>Description: </p> * <p>Company: Helios Development Group LLC</p> * @author Whitehead (nwhitehead AT heliosdev DOT org) * <p><code>com.heliosapm.tsdblite.handlers.WebSocketServerHandler</code></p> */ public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> { /** A map of websock handlers keyed by the op code */ protected final Map<String, WebSocketRequestHandler> handlers = new ConcurrentHashMapV8<String, WebSocketRequestHandler>(); /** * Creates a new WebSocketServerHandler */ public WebSocketServerHandler() { super(true); handlers.putAll(SubscriptionRequestHandlers.registerAll()); } private static final String WEBSOCKET_PATH = "/ws"; private WebSocketServerHandshaker handshaker; @Override public void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception { if (msg instanceof HttpRequest) { final HttpRequest httpR = (HttpRequest) msg; //handleHttpRequest(ctx, (FullHttpRequest) msg); if (WEBSOCKET_PATH.equals(httpR.uri())) { if (httpR instanceof FullHttpRequest) { handleHttpRequest(ctx, (FullHttpRequest) httpR); } } else { HttpRequestManager.getInstance().channelRead(ctx, msg); //.messageReceived(ctx, (HttpRequest)msg); } } else if (msg instanceof WebSocketFrame) { handleWebSocketFrame(ctx, (WebSocketFrame) msg); } } @Override public void channelReadComplete(ChannelHandlerContext ctx) { ctx.flush(); } private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) { // Handle a bad request. if (!req.decoderResult().isSuccess()) { sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST)); return; } // Allow only GET methods. if (req.method() != GET) { sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN)); return; } if ("/favicon.ico".equals(req.uri())) { FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, NOT_FOUND); sendHttpResponse(ctx, req, res); return; } // Handshake WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(getWebSocketLocation(req), null, true); handshaker = wsFactory.newHandshaker(req); if (handshaker == null) { WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel()); } else { handshaker.handshake(ctx.channel(), req); ctx.writeAndFlush( new TextWebSocketFrame("{\"session\" : \"" + ctx.channel().id().asShortText() + "\"}")); } } private void handleWebSocketFrame(final ChannelHandlerContext ctx, final WebSocketFrame frame) { // Check for closing frame if (frame instanceof CloseWebSocketFrame) { handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain()); return; } if (frame instanceof PingWebSocketFrame) { ctx.channel().write(new PongWebSocketFrame(frame.content().retain())); return; } final JsonNode node = JSON.parseToNode(frame.content()); long rid = -1; String session = ""; String op = null; try { rid = node.get("rid").asLong(); } catch (Exception ex) { /* No Op */ } try { session = node.get("session").asText(); } catch (Exception ex) { /* No Op */ } try { op = node.get("op").asText(); } catch (Exception ex) { /* No Op */ } if (op == null) { sendWebSockError(ctx, rid, session, "Request had no op code", null); return; } final WebSocketRequestHandler handler = handlers.get(op.toLowerCase().trim()); if (handler == null) { sendWebSockError(ctx, rid, session, "Unrecognized op code: [" + op + "]", null); } try { handler.processRequest(new WebSocketRequest(ctx, ctx.channel(), node)); } catch (Exception ex) { sendWebSockError(ctx, rid, session, "Failed to process WebSock Request: [" + op + "]", ex); } return; } private static void sendWebSockError(final ChannelHandlerContext ctx, final Number rid, final String session, final String error, final Throwable t) { final String ts; if (t != null) { final StringWriter sw = new StringWriter(); final PrintWriter pw = new PrintWriter(sw, true); sw.flush(); t.printStackTrace(pw); ts = sw.toString(); } else { ts = null; } ctx.writeAndFlush(new TextWebSocketFrame(JSON.serializeToBuf( FluentMap.newMap(MapType.LINK, String.class, Object.class).fput("error", error).fput("rid", rid) .sfput("session", session).sfput("trace", ts).asMap(LinkedHashMap.class)))); } private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) { // Generate an error page if response getStatus code is not OK (200). if (res.status().code() != 200) { ByteBuf buf = Unpooled.copiedBuffer(res.status().toString(), CharsetUtil.UTF_8); res.content().writeBytes(buf); buf.release(); HttpUtil.setContentLength(res, res.content().readableBytes()); } // Send the response and close the connection if necessary. ChannelFuture f = ctx.channel().writeAndFlush(res); if (!HttpUtil.isKeepAlive(req) || res.status().code() != 200) { f.addListener(ChannelFutureListener.CLOSE); } } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { cause.printStackTrace(); ctx.close(); } private static String getWebSocketLocation(FullHttpRequest req) { String location = req.headers().get(HOST) + WEBSOCKET_PATH; return "ws://" + location; } }