1 /*
2 * Copyright 2007-2012 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springbyexample.cometd.continuation;
18
19 import java.util.Map;
20
21 import javax.servlet.ServletException;
22
23 import org.mortbay.cometd.AbstractBayeux;
24 import org.mortbay.cometd.continuation.ContinuationCometdServlet;
25 import org.springframework.web.context.support.WebApplicationContextUtils;
26
27 /**
28 * A continuation comet servlet meant to be used along with
29 * {@link SpringContinuationBayeux}. This servlet overrides the
30 * default intialization of the bayeux instance because the
31 * {@link SpringContinuationBayeux} fully initializes itself using
32 * a Spring configuration.
33 *
34 * @author David Winterfeldt
35 */
36 public class SpringContinuationCometdServlet extends ContinuationCometdServlet {
37
38 private static final long serialVersionUID = 6186673799799707142L;
39
40 /**
41 * <p>Gets bayeux instance configured by Spring
42 * and sets <code>asyncDeliver</code> from the servlet init parameters.</p>
43 *
44 * <p>Throws a <code>ServletException</code> if it can't find
45 * a unique Spring bean of the type <code>AbstractBayeux</code>.</p>
46 *
47 * <p>Overrides <code>AbstractCometdServlet.init()</code> because
48 * {@link SpringContinuationBayeux} handles it's own initialization.</p>
49 */
50 @Override
51 @SuppressWarnings("unchecked")
52 public void init() throws ServletException {
53 synchronized (SpringContinuationCometdServlet.class) {
54 Map<String, AbstractBayeux> hBayeuxBeans = (Map<String, AbstractBayeux>)WebApplicationContextUtils.getWebApplicationContext(getServletContext()).getBeansOfType(AbstractBayeux.class);
55
56 if (hBayeuxBeans == null || hBayeuxBeans.size() != 1) {
57 throw new ServletException("Unable to find a unique Spring bean of the type AbstractBayeux.");
58 }
59
60 for (AbstractBayeux bayeux : hBayeuxBeans.values()) {
61 _bayeux = bayeux;
62 break;
63 }
64 }
65
66 String async = getInitParameter("asyncDeliver");
67
68 if (async!=null) {
69 _asyncDeliver = Boolean.parseBoolean(async);
70 }
71 }
72
73 }