Java tutorial
/* * Copyright 2012 JBoss, by Red Hat, Inc * * 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 org.jboss.errai.bus.server.io.websockets; 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.HttpMethod.GET; import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN; 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.Channel; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandler.Sharable; 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.HttpHeaders; import io.netty.handler.codec.http.HttpRequest; 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.io.BufferedReader; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.security.Principal; import java.util.Collection; import java.util.Enumeration; import java.util.HashMap; import java.util.Iterator; import java.util.Locale; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import javax.servlet.AsyncContext; import javax.servlet.DispatcherType; import javax.servlet.RequestDispatcher; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.ServletInputStream; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import javax.servlet.http.Part; import org.jboss.errai.bus.client.api.QueueSession; import org.jboss.errai.bus.client.api.messaging.Message; import org.jboss.errai.bus.client.protocols.BusCommand; import org.jboss.errai.bus.server.api.MessageQueue; import org.jboss.errai.bus.server.io.DirectDeliveryHandler; import org.jboss.errai.bus.server.io.MessageFactory; import org.jboss.errai.bus.server.service.ErraiService; import org.jboss.errai.bus.server.util.LocalContext; import org.jboss.errai.common.client.protocols.MessageParts; import org.jboss.errai.marshalling.client.api.json.EJObject; import org.jboss.errai.marshalling.client.api.json.EJString; import org.jboss.errai.marshalling.client.api.json.EJValue; import org.jboss.errai.marshalling.server.JSONDecoder; /** * The working prototype ErraiBus Websocket Server. */ @Sharable public class WebSocketServerHandler extends SimpleChannelInboundHandler { public static final String SESSION_ATTR_WS_STATUS = "WebSocketStatus"; public static final String WEBSOCKET_AWAIT_ACTIVATION = "AwaitingActivation"; public static final String WEBSOCKET_ACTIVE = "Active"; public static final String WEBSOCKET_PATH = "/websocket.bus"; private final Map<Channel, QueueSession> activeChannels = new ConcurrentHashMap<Channel, QueueSession>(); private WebSocketServerHandshaker handshaker = null; private ErraiService svc; public WebSocketServerHandler(final ErraiService bus) { this.svc = bus; } @Override protected void channelRead0(ChannelHandlerContext ctx, Object msg) throws Exception { if (msg instanceof FullHttpRequest) { handleHttpRequest(ctx, (FullHttpRequest) msg); } else if (msg instanceof WebSocketFrame) { handleWebSocketFrame(ctx, (WebSocketFrame) msg); } } @Override public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { ctx.flush(); } private void handleHttpRequest(final ChannelHandlerContext ctx, final FullHttpRequest req) throws Exception { // Allow only GET methods. if (req.getMethod() != GET) { sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN)); return; } // Handshake final WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory( this.getWebSocketLocation(req), null, false); this.handshaker = wsFactory.newHandshaker(req); if (this.handshaker == null) { wsFactory.sendUnsupportedWebSocketVersionResponse(ctx.channel()); } else { this.handshaker.handshake(ctx.channel(), req); } } private void handleWebSocketFrame(final ChannelHandlerContext ctx, final WebSocketFrame frame) { // Check for closing frame if (frame instanceof CloseWebSocketFrame) { activeChannels.remove(ctx.channel()); this.handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain()); return; } 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())); } @SuppressWarnings("unchecked") final EJValue val = JSONDecoder.decode(((TextWebSocketFrame) frame).text()); final QueueSession session; // this is not an active channel. if (!activeChannels.containsKey(ctx.channel())) { if (val == null) { sendMessage(ctx, getFailedNegotiation("illegal handshake")); return; } final EJObject ejObject = val.isObject(); if (ejObject == null) { return; } final EJValue ejValue = ejObject.get(MessageParts.CommandType.name()); if (ejValue.isNull()) { sendMessage(ctx, getFailedNegotiation("illegal handshake")); } final String commandType = ejValue.isString().stringValue(); // this client apparently wants to connect. if (BusCommand.Associate.name().equals(commandType)) { final String sessionKey = ejObject.get(MessageParts.ConnectionSessionKey.name()).isString() .stringValue(); // has this client already attempted a connection, and is in a wait verify state if (sessionKey != null && (session = svc.getBus().getSessionBySessionId(sessionKey)) != null) { final LocalContext localContext = LocalContext.get(session); if (localContext.hasAttribute(SESSION_ATTR_WS_STATUS) && WEBSOCKET_ACTIVE .equals(localContext.getAttribute(String.class, SESSION_ATTR_WS_STATUS))) { final MessageQueue queueBySession = svc.getBus().getQueueBySession(sessionKey); queueBySession.setDeliveryHandler( DirectDeliveryHandler.createFor(new NettyQueueChannel(ctx.channel()))); // open the channel activeChannels.put(ctx.channel(), session); ctx.channel().closeFuture().addListener(new ChannelFutureListener() { @Override public void operationComplete(final ChannelFuture channelFuture) throws Exception { activeChannels.remove(ctx.channel()); queueBySession.setDeliveryHandlerToDefault(); } }); // set the session queue into direct channel mode. localContext.removeAttribute(SESSION_ATTR_WS_STATUS); // service.schedule(new Runnable() { // @Override // public void run() { // ctx.getChannel().close(); // } // }, 5, TimeUnit.SECONDS); return; } // check the activation key matches. final EJString activationKey = ejObject.get(MessageParts.WebSocketToken.name()).isString(); if (activationKey == null || !WebSocketTokenManager.verifyOneTimeToken(session, activationKey.stringValue())) { // nope. go away! sendMessage(ctx, getFailedNegotiation("bad negotiation key")); } else { // the key matches. now we send the reverse challenge to prove this client is actually // already talking to the bus over the COMET channel. final String reverseToken = WebSocketTokenManager.getNewOneTimeToken(session); localContext.setAttribute(MessageParts.WebSocketToken.name(), reverseToken); localContext.setAttribute(SESSION_ATTR_WS_STATUS, WEBSOCKET_AWAIT_ACTIVATION); // send the challenge. sendMessage(ctx, getReverseChallenge(reverseToken)); return; } sendMessage(ctx, getSuccessfulNegotiation()); } else { sendMessage(ctx, getFailedNegotiation("bad session id")); } } else { sendMessage(ctx, getFailedNegotiation("bad command")); } } else { // this is an active session. send the message. session = activeChannels.get(ctx.channel()); for (final Message msg : MessageFactory.createCommandMessage(session, val)) { msg.setResource(HttpServletRequest.class.getName(), new SyntheticHttpServletRequest()); svc.store(msg); } } } private void sendHttpResponse(final ChannelHandlerContext ctx, final FullHttpRequest req, final FullHttpResponse res) { // Generate an error page if response status code is not OK (200). 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()); } // Send the response and close the connection if necessary. final ChannelFuture f = ctx.channel().write(res); if (!isKeepAlive(req) || res.getStatus().code() != 200) { f.addListener(ChannelFutureListener.CLOSE); } } private String getWebSocketLocation(final HttpRequest req) { return "ws://" + req.headers().get(HttpHeaders.Names.HOST) + WEBSOCKET_PATH; } public static void sendMessage(final ChannelHandlerContext ctx, final String message) { ctx.channel().writeAndFlush(new TextWebSocketFrame(message)); } private static String getFailedNegotiation(final String error) { return "[{\"" + MessageParts.ToSubject.name() + "\":\"ClientBus\", \"" + MessageParts.CommandType.name() + "\":\"" + BusCommand.WebsocketNegotiationFailed.name() + "\"," + "\"" + MessageParts.ErrorMessage.name() + "\":\"" + error + "\"}]"; } private static String getSuccessfulNegotiation() { return "[{\"" + MessageParts.ToSubject.name() + "\":\"ClientBus\", \"" + MessageParts.CommandType.name() + "\":\"" + BusCommand.WebsocketChannelOpen.name() + "\"}]"; } private static String getReverseChallenge(final String token) { return "[{\"" + MessageParts.ToSubject.name() + "\":\"ClientBus\", \"" + MessageParts.CommandType.name() + "\":\"" + BusCommand.WebsocketChannelVerify.name() + "\",\"" + MessageParts.WebSocketToken + "\":\"" + token + "\"}]"; } public void stop() { for (final Channel channel : activeChannels.keySet()) { channel.close(); } } private static class SyntheticHttpServletRequest implements HttpServletRequest { private final Map<String, Object> attributes = new HashMap<String, Object>(); private final Map<String, String[]> parameters = new HashMap<String, String[]>(); @Override public Object getAttribute(final String name) { return attributes.get(name); } @Override public Enumeration<String> getAttributeNames() { return new Enumeration<String>() { private final Iterator<String> stringIterator = attributes.keySet().iterator(); @Override public boolean hasMoreElements() { return stringIterator.hasNext(); } @Override public String nextElement() { return stringIterator.next(); } }; } @Override public String getCharacterEncoding() { return "UTF-8"; } @Override public void setCharacterEncoding(final String env) throws UnsupportedEncodingException { } @Override public int getContentLength() { return 0; } @Override public String getContentType() { return null; } @Override public ServletInputStream getInputStream() throws IOException { return null; } @Override public String getParameter(final String name) { final String[] parms = parameters.get(name); if (parms == null) { return null; } else { return parms[0]; } } @Override public Enumeration<String> getParameterNames() { return new Enumeration<String>() { private final Iterator<String> stringIterator = parameters.keySet().iterator(); @Override public boolean hasMoreElements() { return stringIterator.hasNext(); } @Override public String nextElement() { return stringIterator.next(); } }; } @Override public String[] getParameterValues(final String name) { return parameters.get(name); } @Override public Map<String, String[]> getParameterMap() { return parameters; } @Override public String getProtocol() { return null; } @Override public String getScheme() { return null; } @Override public String getServerName() { return null; } @Override public int getServerPort() { return 0; } @Override public BufferedReader getReader() throws IOException { return null; } @Override public String getRemoteAddr() { return null; } @Override public String getRemoteHost() { return null; } @Override public void setAttribute(final String name, final Object o) { attributes.put(name, o); } @Override public void removeAttribute(final String name) { attributes.remove(name); } @Override public Locale getLocale() { return null; } @Override public Enumeration<Locale> getLocales() { return null; } @Override public boolean isSecure() { return false; } @Override public RequestDispatcher getRequestDispatcher(final String path) { return null; } @Override public String getRealPath(final String path) { return null; } @Override public int getRemotePort() { return 0; } @Override public String getLocalName() { return null; } @Override public String getLocalAddr() { return null; } @Override public int getLocalPort() { return 0; } @Override public ServletContext getServletContext() { return null; } @Override public AsyncContext startAsync() throws IllegalStateException { return null; } @Override public AsyncContext startAsync(final ServletRequest servletRequest, final ServletResponse servletResponse) throws IllegalStateException { return null; } @Override public boolean isAsyncStarted() { return false; } @Override public boolean isAsyncSupported() { return false; } @Override public AsyncContext getAsyncContext() { return null; } @Override public DispatcherType getDispatcherType() { return null; } @Override public String getAuthType() { return null; } @Override public Cookie[] getCookies() { return new Cookie[0]; } @Override public long getDateHeader(final String name) { return 0; } @Override public String getHeader(final String name) { return null; } @Override public Enumeration<String> getHeaders(final String name) { return null; } @Override public Enumeration<String> getHeaderNames() { return null; } @Override public int getIntHeader(final String name) { return 0; } @Override public String getMethod() { return null; } @Override public String getPathInfo() { return null; } @Override public String getPathTranslated() { return null; } @Override public String getContextPath() { return null; } @Override public String getQueryString() { return null; } @Override public String getRemoteUser() { return null; } @Override public boolean isUserInRole(final String role) { return false; } @Override public Principal getUserPrincipal() { return null; } @Override public String getRequestedSessionId() { return null; } @Override public String getRequestURI() { return null; } @Override public StringBuffer getRequestURL() { return null; } @Override public String getServletPath() { return null; } @Override public HttpSession getSession(final boolean create) { return null; } @Override public HttpSession getSession() { return null; } @Override public boolean isRequestedSessionIdValid() { return false; } @Override public boolean isRequestedSessionIdFromCookie() { return false; } @Override public boolean isRequestedSessionIdFromURL() { return false; } @Override public boolean isRequestedSessionIdFromUrl() { return false; } @Override public boolean authenticate(final HttpServletResponse response) throws IOException, ServletException { return false; } @Override public void login(final String username, final String password) throws ServletException { } @Override public void logout() throws ServletException { } @Override public Collection<Part> getParts() throws IOException, ServletException { return null; } @Override public Part getPart(final String name) throws IOException, ServletException { return null; } } }