1 // Copyright (c) 2000 Just Objects B.V. <just@justobjects.nl>
2 // Distributable under LGPL license. See terms of license at gnu.org.
3 
4 package nl.justobjects.pushlet.servlet;
5 
6 import nl.justobjects.pushlet.core.*;
7 import nl.justobjects.pushlet.util.Log;
8 import nl.justobjects.pushlet.util.Servlets;
9 import nl.justobjects.pushlet.util.PushletException;
10import nl.justobjects.pushlet.Version;
11
12import javax.servlet.ServletException;
13import javax.servlet.http.HttpServlet;
14import javax.servlet.http.HttpServletRequest;
15import javax.servlet.http.HttpServletResponse;
16import java.io.IOException;
17import java.io.InputStreamReader;
18import java.util.Enumeration;
19
20/**
21 * Servlet runs a Subscriber per request.
22 *
23 * @author Just van den Broecke - Just Objects &copy;
24 * @version $Id: Pushlet.java,v 1.22 2007/11/24 10:29:36 justb Exp $
25 */
26public class Pushlet extends HttpServlet implements Protocol {
27
28    public void init() throws ServletException {
29        // Load configuration (from classpath or WEB-INF root path)
30        String webInfPath = getServletContext().getRealPath("/") + "/WEB-INF";
31        Config.load(webInfPath);
32
33        Log.init();
34
35        // Start
36        Log.info("init() Pushlet Webapp - version=" + Version.SOFTWARE_VERSION + " built=" + Version.BUILD_DATE);
37
38        // Start session manager
39        SessionManager.getInstance().start();
40
41        // Start event Dispatcher
42        Dispatcher.getInstance().start();
43
44
45        if (Config.getBoolProperty(Config.SOURCES_ACTIVATE)) {
46            EventSourceManager.start(webInfPath);
47        } else {
48            Log.info("Not starting local event sources");
49        }
50    }
51
52    public void destroy() {
53        Log.info("destroy(): Exit Pushlet webapp");
54
55        if (Config.getBoolProperty(Config.SOURCES_ACTIVATE)) {
56            // Stop local event sources
57            EventSourceManager.stop();
58        } else {
59            Log.info("No local event sources to stop");
60        }
61
62        // Should abort all subscribers
63        Dispatcher.getInstance().stop();
64
65        // Should stop all sessions
66        SessionManager.getInstance().stop();
67    }
68
69    /**
70     * Servlet GET request: handles event requests.
71     */
72    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
73        Event event = null;
74
75        try {
76            // Event parm identifies event type from the client
77            String eventType = Servlets.getParameter(request, P_EVENT);
78
79            // Always must have an event type
80            if (eventType == null) {
81                Log.warn("Pushlet.doGet(): bad request, no event specified");
82                response.sendError(HttpServletResponse.SC_BAD_REQUEST, "No eventType specified");
83                return;
84            }
85
86            // Create Event and set attributes from parameters
87            event = new Event(eventType);
88            for (Enumeration e = request.getParameterNames(); e.hasMoreElements();) {
89                String nextAttribute = (String) e.nextElement();
90                event.setField(nextAttribute, request.getParameter(nextAttribute));
91            }
92
93
94        } catch (Throwable t) {
95            // Error creating event
96            Log.warn("Pushlet: Error creating event in doGet(): ", t);
97            response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
98            return;
99        }
00
01        // Handle parsed request
02        doRequest(event, request, response);
03
04    }
05
06    /**
07     * Servlet POST request: extracts event data from body.
08     */
09    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
10        Event event = null;
11        try {
12            // Create Event by parsing XML from input stream.
13            event = EventParser.parse(new InputStreamReader(request.getInputStream()));
14
15            // Always must have an event type
16            if (event.getEventType() == null) {
17                Log.warn("Pushlet.doPost(): bad request, no event specified");
18                response.sendError(HttpServletResponse.SC_BAD_REQUEST, "No eventType specified");
19                return;
20            }
21
22
23        } catch (Throwable t) {
24            // Error creating event
25            Log.warn("Pushlet:  Error creating event in doPost(): ", t);
26            response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
27            return;
28        }
29
30        // Handle parsed request
31        doRequest(event, request, response);
32
33    }
34
35    /**
36     * Generic request handler (GET+POST).
37     */
38    protected void doRequest(Event anEvent, HttpServletRequest request, HttpServletResponse response) {
39        // Must have valid event type.
40        String eventType = anEvent.getEventType();
41        try {
42
43            // Get Session: either by creating (on Join eventType)
44            // or by id (any other eventType, since client is supposed to have joined).
45            Session session = null;
46            if (eventType.startsWith(Protocol.E_JOIN)) {
47                // Join request: create new subscriber
48                session = SessionManager.getInstance().createSession(anEvent);
49
50                String userAgent = request.getHeader("User-Agent");
51                if (userAgent != null) {
52                    userAgent = userAgent.toLowerCase();
53                } else {
54                    userAgent = "unknown";
55                }
56                session.setUserAgent(userAgent);
57
58            } else {
59                // Must be a request for existing Session
60
61                // Get id
62                String id = anEvent.getField(P_ID);
63
64                // We must have an id value
65                if (id == null) {
66                    response.sendError(HttpServletResponse.SC_BAD_REQUEST, "No id specified");
67                    Log.warn("Pushlet: bad request, no id specified event=" + eventType);
68                    return;
69                }
70
71                // We have an id: get the session object
72                session = SessionManager.getInstance().getSession(id);
73
74                // Check for invalid id
75                if (session == null) {
76                    response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Invalid or expired id: " + id);
77                    Log.warn("Pushlet:  bad request, no session found id=" + id + " event=" + eventType);
78                    return;
79                }
80            }
81
82            // ASSERTION: we have a valid Session
83
84            // Let Controller handle request further
85            // including exceptions
86            Command command = Command.create(session, anEvent, request, response);
87            session.getController().doCommand(command);
88        } catch (Throwable t) {
89            // Hmm we should never ever get here
90            Log.warn("Pushlet:  Exception in doRequest() event=" + eventType, t);
91            t.printStackTrace();
92            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
93        }
94
95    }
96}
97
98/*
99 * $Log: Pushlet.java,v $
00 * Revision 1.22  2007/11/24 10:29:36  justb
01 * add hooks for custom logging (you can override DefaultLogger in pushlet.properties)
02 *
03 * Revision 1.21  2007/11/23 21:10:17  justb
04 * add hooks for custom logging (you can override DefaultLogger in pushlet.properties)
05 *
06 * Revision 1.20  2007/11/10 13:44:02  justb
07 * pushlet.properties and sources.properties can now also be put under WEB-INF
08 *
09 * Revision 1.19  2006/05/15 11:52:53  justb
10 * updates mainly for AJAX client
11 *
12 * Revision 1.18  2005/02/28 15:58:05  justb
13 * added SimpleListener example
14 *
15 * Revision 1.17  2005/02/28 13:06:01  justb
16 * introduced join-listen protocol service
17 *
18 * Revision 1.16  2005/02/28 12:45:59  justb
19 * introduced Command class
20 *
21 * Revision 1.15  2005/02/28 09:14:56  justb
22 * sessmgr/dispatcher factory/singleton support
23 *
24 * Revision 1.14  2005/02/25 15:13:04  justb
25 * session id generation more robust
26 *
27 * Revision 1.13  2005/02/21 17:19:21  justb
28 * move init()/destroy() to Pushlet servlet
29 *
30 * Revision 1.12  2005/02/21 16:59:17  justb
31 * SessionManager and session lease introduced
32 *
33 * Revision 1.11  2005/02/21 11:50:47  justb
34 * ohase1 of refactoring Subscriber into Session/Controller/Subscriber
35 *
36 * Revision 1.10  2005/02/20 13:05:32  justb
37 * removed the Postlet (integrated in Pushlet protocol)
38 *
39 * Revision 1.9  2005/02/18 10:07:23  justb
40 * many renamings of classes (make names compact)
41 *
42 * Revision 1.8  2005/01/13 14:47:15  justb
43 * control evt: send response on same (control) connection
44 *
45 * Revision 1.7  2004/10/24 12:58:18  justb
46 * revised client and test classes for new protocol
47 *
48 * Revision 1.6  2004/09/26 21:39:44  justb
49 * allow multiple subscriptions and out-of-band requests
50 *
51 * Revision 1.5  2004/09/20 22:01:40  justb
52 * more changes for new protocol
53 *
54 * Revision 1.4  2004/09/03 22:35:37  justb
55 * Almost complete rewrite, just checking in now
56 *
57 * Revision 1.3  2004/08/13 23:36:06  justb
58 * rewrite of Pullet into Pushlet "pull" mode
59 *
60 * Revision 1.2  2003/08/15 08:37:40  justb
61 * fix/add Copyright+LGPL file headers and footers
62 *
63 * Revision 1.1  2003/08/13 13:26:57  justb
64 * moved all servlets to servlet package
65 *
66 * Revision 1.2  2003/05/18 16:15:08  justb
67 * support for XML encoded Events
68 *
69 * Revision 1.1.1.1  2002/09/24 21:02:32  justb
70 * import to sourceforge
71 *
72 * Revision 1.1.1.1  2002/09/20 22:48:18  justb
73 * import to SF
74 *
75 * Revision 1.1.1.1  2002/09/20 14:19:04  justb
76 * first import into SF
77 *
78 * Revision 1.3  2002/04/15 20:42:41  just
79 * reformatting and renaming GuardedQueue to EventQueue
80 *
81 * Revision 1.2  2000/08/21 20:48:29  just
82 * added CVS log and id tags plus copyrights
83 *
84 *
85 */
86
87