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Java > Open Source Codes > org > enhydra > barracuda > core > event > events > LongRunningEventGateway


1 /*
2  * Copyright (C) 2003 Christian Cryder [christianc@granitepeaks.com]
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with this library; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  *
18  * $Id: LongRunningEventGateway.java,v 1.2 2004/02/01 05:16:28 christianc Exp $
19  */
20 package org.enhydra.barracuda.core.event.events;
21
22 import java.io.*;
23 import java.util.*;
24 import java.net.*;
25 import javax.servlet.*;
26 import javax.servlet.http.*;
27
28 import org.apache.log4j.*;
29
30 import org.enhydra.barracuda.core.comp.*;
31 import org.enhydra.barracuda.core.event.*;
32 import org.enhydra.barracuda.core.event.helper.*;
33 import org.enhydra.barracuda.core.helper.servlet.*;
34 import org.enhydra.barracuda.plankton.*;
35 import org.enhydra.barracuda.plankton.data.*;
36 //import org.enhydra.barracuda.plankton.http.*;
37 import org.enhydra.barracuda.core.util.dom.*;
38 import org.enhydra.barracuda.core.util.http.*;
39 import org.enhydra.barracuda.core.event.events.xmlc.*;
40
41
42 /**
43  * Event handlers (both Controller and View) for the LongRunning events
44  */
45 public class LongRunningEventGateway extends DefaultEventGateway {
46
47     //public constants
48 protected static final Logger logger = Logger.getLogger(LongRunningEventGateway.class.getName());
49
50     //configurable through object repos assembler
51 public static Class JavaDoc DEFAULT_TEMPLATE = LongRunningHTML.class;
52     public static int DEFAULT_ETA = 180;
53     public static int DEFAULT_REFRESH_RATE = 3;
54
55     //Get_Data directives supported
56 public static final String JavaDoc CHECK_LONG_RUNNING = "CheckLongRunning"; //(BAction)
57 public static final String JavaDoc CANCEL_LONG_RUNNING = "CancelLongRunning"; //(BAction)
58 public static final String JavaDoc TIME_ETA = "TimeETA"; //(String describing ETA in hours, minutes, and secs)
59 public static final String JavaDoc TIME_ELAPSED = "TimeElapsed"; //(String describing ETA in hours, minutes, and secs)
60 public static final String JavaDoc TIME_REMAINING = "TimeRemaining"; //(String describing ETA in hours, minutes, and secs)
61 public static final String JavaDoc PERCENT_COMPLETE = "PercentComplete"; //(int)
62 public static final String JavaDoc PERCENT_REMAINING = "PercentRemaining"; //(int)
63 public static final String JavaDoc STATEMAP_VALUE = "StateMapValue"; //(String - data portion of TemplateDirective used as StateMap key)
64 public static final String JavaDoc REFRESH_RATE = "RefreshRate"; //(int - in seconds)
65
66     //req params
67 public static final String JavaDoc LRG_ID = "$lrgid"; //(String)
68
69     //this defines the various event handlers
70 private ListenerFactory baseLongRunningFactory = new DefaultListenerFactory() {public BaseEventListener getInstance() {return new BaseLongRunningHandler();} public String JavaDoc getListenerID() {return getID(BaseLongRunningHandler.class);}};
71     private ListenerFactory checkLongRunningFactory = new EventForwardingFactory(new RenderLongRunningEvent());
72     private ListenerFactory cancelLongRunningFactory = new DefaultListenerFactory() {public BaseEventListener getInstance() {return new CancelLongRunningHandler();} public String JavaDoc getListenerID() {return getID(CancelLongRunningHandler.class);}};
73     private ListenerFactory renderLongRunningFactory = new DefaultListenerFactory() {public BaseEventListener getInstance() {return new RenderLongRunningHandler();} public String JavaDoc getListenerID() {return getID(RenderLongRunningHandler.class);}};
74
75
76
77
78     /**
79      * Public constructor
80      */
81     public LongRunningEventGateway() {
82         //specify who's interested in what
83 specifyLocalEventInterests(baseLongRunningFactory, LongRunningEvent.class);
84         specifyLocalEventInterests(checkLongRunningFactory, CheckLongRunningEvent.class);
85         specifyLocalEventInterests(cancelLongRunningFactory, CancelLongRunningEvent.class);
86         specifyLocalEventInterests(renderLongRunningFactory, RenderLongRunningEvent.class);
87     }
88
89
90     //------------------------------------------------------------
91 // Model 2 - Controller Event Handlers
92 //------------------------------------------------------------
93 /**
94      * Gets invoked for both CheckLongRunningEvent and CancelLongRunningEvent.
95      * Basically just makes sure that everything needed (lrid and dresp) is
96      * available before continuing.
97      */
98     class BaseLongRunningHandler extends DefaultBaseEventListener {
99         public void handleControlEvent(ControlEventContext context) throws EventException, ServletException, IOException {
100             //get the basic objects
101 ObjectRepository session = ObjectRepository.getSessionRepository();
102             ObjectRepository lor = ObjectRepository.getLocalRepository();
103             HttpServletRequest req = (HttpServletRequest) lor.getState(ApplicationGateway.HTTP_SERVLET_REQUEST);
104             HttpServletResponse resp = (HttpServletResponse) lor.getState(ApplicationGateway.HTTP_SERVLET_RESPONSE);
105
106             //get the lrid
107 String JavaDoc lrid = req.getParameter(LRG_ID);
108             logger.info("invoking CheckLongRunningHandler, for "+LRG_ID+"="+lrid);
109
110             //if we don't have any accompanying lrid, err
111 if (lrid==null) {
112                 resp.sendError(HttpServletResponse.SC_GONE, "This event was missing a long running target ID. Please try running the report again.");
113                 return;
114             } else {
115                 lor.putState(LRG_ID, lrid);
116             }
117
118             //if there is no DeferredResponseWrapper living in the session for this lrid, err
119 DeferredResponseWrapper dresp = (DeferredResponseWrapper) session.getState(lrid);
120             if (dresp==null) {
121                 resp.sendError(HttpServletResponse.SC_GONE, "This long running response was missing from the session. The long running report has either completed or been canceled.");
122                 return;
123             } else {
124                 lor.putState(lrid, dresp);
125             }
126
127             //sit and spin until we have a LongRunning object available in the dresp
128 //(what happens is the CheckLongRunningEvent handler gets dispatched at the same time as
129 //the request to actually execute the long running task - this means we may actually be handling
130 //this request before the LongRunning object has been added to the dresp yet...so if its not
131 //there, we want to sit and spin a bit until we get it; if it doesn't show up after 5 secs, something
132 //is wrong)
133 int tryCntr = 0;
134             while (dresp.getLongRunning()==null) {
135                 try {
136                     if (++tryCntr>50) {
137                         resp.sendError(HttpServletResponse.SC_GONE, "This LongRunning object never showed up in the DeferredResponseWrapper. Aborting LongRunningHandler...");
138                         return;
139                     }
140                     Thread.currentThread().sleep(100);
141                 } catch (InterruptedException JavaDoc e) {
142                 }
143             }
144         }
145     }
146
147     /**
148      * Actually cancel the long running process
149      */
150     class CancelLongRunningHandler extends DefaultBaseEventListener {
151         public void handleControlEvent(ControlEventContext context) throws EventException, ServletException, IOException {
152
153             //get the dresp obj
154 ObjectRepository session = ObjectRepository.getSessionRepository();
155             ObjectRepository lor = ObjectRepository.getLocalRepository();
156             HttpServletRequest req = (HttpServletRequest) lor.getState(ApplicationGateway.HTTP_SERVLET_REQUEST);
157             HttpServletResponse resp = (HttpServletResponse) lor.getState(ApplicationGateway.HTTP_SERVLET_RESPONSE);
158             String JavaDoc lrid = (String JavaDoc) lor.getState(LRG_ID);
159             DeferredResponseWrapper dresp = (DeferredResponseWrapper) lor.getState(lrid);
160
161             //get the LongRunning object so we can see where to go from here
162 LongRunning lr = (LongRunning) dresp.getLongRunning();
163
164             //stop the dresp
165 dresp.interrupt();
166
167             //clean up the session
168 session.removeState(lrid+"*");
169
170             //get the redirect url. If none is specified, simply write an error response
171 resp.setContentType("text/html");
172             StringBuffer JavaDoc sb = new StringBuffer JavaDoc(500);
173             BaseEvent redirectEvent = lr.getRedirectEvent();
174             if (redirectEvent==null) {
175                 if (logger.isInfoEnabled()) logger.info("LongRunning processes cancelled, generating default description");
176                 sb.append("<html>");
177                 sb.append(" <head>");
178                 sb.append(" <title>Cancelled</title>");
179                 sb.append(" </head>");
180                 sb.append(" <body>");
181                 sb.append(" <h1>Cancelled.</h1>");
182                 sb.append(" <p>The Long Running process was cancelled.");
183                 sb.append(" </body>");
184                 sb.append("</html>");
185             
186             //...otherwise, redirect the browser
187 } else {
188                 //request the browser to redirect accordingly
189 ClientSideRedirectException re = new ClientSideRedirectException(redirectEvent);
190                 String JavaDoc rdURL = URLRewriter.encodeRedirectURL(req, resp, re.getRedirectURL());
191                 if (logger.isInfoEnabled()) logger.info("LongRunning processes cancelled, redirecting to "+rdURL);
192                 sb.append("<html>");
193                 sb.append(" <head>");
194                 sb.append(" <title>Redirecting...</title>");
195                 sb.append(" </head>");
196 // sb.append(" <body onload=\"window.top.pageFullyLoaded=true; window.top.location.replace('"+rdURL+"');\">");
197 sb.append(" <body onload=\"window.top.pageFullyLoaded=true; window.top.location.replace('"+rdURL+"');\" style=\"font-family: Georgia, Arial, Times New Roman\">");
198                 sb.append(" <p>&nbsp;<p>&nbsp;<p>&nbsp;<div style=\"text-align: center\">Cancelling request (this may take a few seconds...)</div>");
199                 sb.append(" </body>");
200                 sb.append("</html>");
201             }
202             String JavaDoc content = sb.toString();
203             Writer wr = resp.getWriter();
204             wr.write(content);
205             wr.close();
206             resp.flushBuffer();
207         }
208     }
209
210
211     //------------------------------------------------------------
212 // Model 2 - View Event Handlers
213 //------------------------------------------------------------
214 /**
215      * RenderLongRunningHandler -
216      */
217     class RenderLongRunningHandler extends BTemplateViewHandler {
218         ObjectRepository lor = ObjectRepository.getLocalRepository();
219         String JavaDoc lrid = (String JavaDoc) lor.getState(LRG_ID);
220         DeferredResponseWrapper dresp = (DeferredResponseWrapper) lor.getState(lrid);
221         LongRunning lr = (LongRunning) dresp.getLongRunning();
222
223         public Object JavaDoc getTemplateModels() {
224             List models = lr.getAdditionalModels();
225             models.add(new LocalTemplateModel());
226             return models;
227         }
228         public Class JavaDoc getTemplateClass() {
229             return lr.getTemplateClass();
230         }
231         public class LocalTemplateModel extends AbstractTemplateModel {
232
233             //register the model by name
234 public String JavaDoc getName() {return "LongRunningModel";}
235
236             //provide items by key
237 public Object JavaDoc getItem(TemplateDirective td) {
238                 String JavaDoc cmd = td.getCommand();
239                 String JavaDoc key = td.getKeyName();
240                 String JavaDoc data = td.getKeyData();
241                 Object JavaDoc item = null;
242         
243                 //get a list of all key/total vals
244 if (key.equals(CHECK_LONG_RUNNING)) {
245                     BAction baction = new BAction(new CheckLongRunningEvent());
246                     baction.setParam(LRG_ID, lrid);
247                     item = baction;
248              
249                 } else if (key.equals(CANCEL_LONG_RUNNING)) {
250                     BAction baction = new BAction(new CancelLongRunningEvent());
251                     baction.setParam(LRG_ID, lrid);
252                     item = baction;
253
254                 } else if (key.equals(TIME_ETA)) {
255                     item = StringUtil.getElapsedStr((long) (lr.getETA()*1000), Calendar.SECOND);
256
257                 } else if (key.equals(TIME_ELAPSED)) {
258                     item = StringUtil.getElapsedStr((long) (lr.getElapsed()*1000), Calendar.SECOND);
259
260                 } else if (key.equals(TIME_REMAINING)) {
261                     int remaining = lr.getETA() - lr.getElapsed();
262                     if (remaining<1) remaining = 1;
263                     item = StringUtil.getElapsedStr((long) (remaining*1000), Calendar.SECOND);
264
265                 } else if (key.equals(PERCENT_COMPLETE)) {
266                     item = lr.getPercentComplete()+"%";
267                     
268                 } else if (key.equals(PERCENT_REMAINING)) {
269                     item = (100 - lr.getPercentComplete())+"%";
270                     
271                 } else if (key.equals(REFRESH_RATE)) {
272                     item = ""+lr.getRefreshRate();
273                     
274                 } else if (key.equals(STATEMAP_VALUE)) {
275                     Object JavaDoc val = lr.getStateMap().getState(data);
276                     item = (val!=null ? val : "[Undefined Statemap Key: "+data+"]");
277                     
278                 } else {
279                     item = super.getItem(td);
280                 }
281                 
282                 //return item
283 return item;
284             }
285         }
286     }
287 }
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