001/*
002 * Copyright 2002-2015 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.socket.sockjs.transport.handler;
018
019import java.io.IOException;
020import java.io.UnsupportedEncodingException;
021import java.util.regex.Pattern;
022
023import org.springframework.http.MediaType;
024import org.springframework.http.server.ServerHttpRequest;
025import org.springframework.http.server.ServerHttpResponse;
026import org.springframework.util.MultiValueMap;
027import org.springframework.util.StringUtils;
028import org.springframework.web.socket.WebSocketHandler;
029import org.springframework.web.socket.sockjs.SockJsException;
030import org.springframework.web.socket.sockjs.frame.SockJsFrame;
031import org.springframework.web.socket.sockjs.frame.SockJsFrameFormat;
032import org.springframework.web.socket.sockjs.transport.SockJsSession;
033import org.springframework.web.socket.sockjs.transport.SockJsSessionFactory;
034import org.springframework.web.socket.sockjs.transport.session.AbstractHttpSockJsSession;
035import org.springframework.web.util.UriComponentsBuilder;
036import org.springframework.web.util.UriUtils;
037
038/**
039 * Base class for HTTP transport handlers that push messages to connected clients.
040 *
041 * @author Rossen Stoyanchev
042 * @since 4.0
043 */
044public abstract class AbstractHttpSendingTransportHandler extends AbstractTransportHandler
045                implements SockJsSessionFactory {
046
047        /**
048         * Pattern for validating jsonp callback parameter values.
049         */
050        private static final Pattern CALLBACK_PARAM_PATTERN = Pattern.compile("[0-9A-Za-z_\\.]*");
051
052
053        @Override
054        public final void handleRequest(ServerHttpRequest request, ServerHttpResponse response,
055                        WebSocketHandler wsHandler, SockJsSession wsSession) throws SockJsException {
056
057                AbstractHttpSockJsSession sockJsSession = (AbstractHttpSockJsSession) wsSession;
058
059                String protocol = null;  // https://github.com/sockjs/sockjs-client/issues/130
060                sockJsSession.setAcceptedProtocol(protocol);
061
062                // Set content type before writing
063                response.getHeaders().setContentType(getContentType());
064
065                handleRequestInternal(request, response, sockJsSession);
066        }
067
068        protected void handleRequestInternal(ServerHttpRequest request, ServerHttpResponse response,
069                        AbstractHttpSockJsSession sockJsSession) throws SockJsException {
070
071                if (sockJsSession.isNew()) {
072                        if (logger.isDebugEnabled()) {
073                                logger.debug(request.getMethod() + " " + request.getURI());
074                        }
075                        sockJsSession.handleInitialRequest(request, response, getFrameFormat(request));
076                }
077                else if (sockJsSession.isClosed()) {
078                        if (logger.isDebugEnabled()) {
079                                logger.debug("Connection already closed (but not removed yet) for " + sockJsSession);
080                        }
081                        SockJsFrame frame = SockJsFrame.closeFrameGoAway();
082                        try {
083                                response.getBody().write(frame.getContentBytes());
084                        }
085                        catch (IOException ex) {
086                                throw new SockJsException("Failed to send " + frame, sockJsSession.getId(), ex);
087                        }
088                }
089                else if (!sockJsSession.isActive()) {
090                        if (logger.isTraceEnabled()) {
091                                logger.trace("Starting " + getTransportType() + " async request.");
092                        }
093                        sockJsSession.handleSuccessiveRequest(request, response, getFrameFormat(request));
094                }
095                else {
096                        if (logger.isDebugEnabled()) {
097                                logger.debug("Another " + getTransportType() + " connection still open for " + sockJsSession);
098                        }
099                        String formattedFrame = getFrameFormat(request).format(SockJsFrame.closeFrameAnotherConnectionOpen());
100                        try {
101                                response.getBody().write(formattedFrame.getBytes(SockJsFrame.CHARSET));
102                        }
103                        catch (IOException ex) {
104                                throw new SockJsException("Failed to send " + formattedFrame, sockJsSession.getId(), ex);
105                        }
106                }
107        }
108
109
110        protected abstract MediaType getContentType();
111
112        protected abstract SockJsFrameFormat getFrameFormat(ServerHttpRequest request);
113
114
115        protected final String getCallbackParam(ServerHttpRequest request) {
116                String query = request.getURI().getQuery();
117                MultiValueMap<String, String> params = UriComponentsBuilder.newInstance().query(query).build().getQueryParams();
118                String value = params.getFirst("c");
119                if (StringUtils.isEmpty(value)) {
120                        return null;
121                }
122                try {
123                        String result = UriUtils.decode(value, "UTF-8");
124                        return (CALLBACK_PARAM_PATTERN.matcher(result).matches() ? result : null);
125                }
126                catch (UnsupportedEncodingException ex) {
127                        // should never happen
128                        throw new SockJsException("Unable to decode callback query parameter", null, ex);
129                }
130        }
131
132}