Source Code Cross Referenced for SCXMLExecutor.java in  » Library » Apache-commons-scxml-0.6-src » org » apache » commons » scxml » Java Source Code / Java DocumentationJava Source Code and Java Documentation

Java Source Code / Java Documentation
1. 6.0 JDK Core
2. 6.0 JDK Modules
3. 6.0 JDK Modules com.sun
4. 6.0 JDK Modules com.sun.java
5. 6.0 JDK Modules sun
6. 6.0 JDK Platform
7. Ajax
8. Apache Harmony Java SE
9. Aspect oriented
10. Authentication Authorization
11. Blogger System
12. Build
13. Byte Code
14. Cache
15. Chart
16. Chat
17. Code Analyzer
18. Collaboration
19. Content Management System
20. Database Client
21. Database DBMS
22. Database JDBC Connection Pool
23. Database ORM
24. Development
25. EJB Server geronimo
26. EJB Server GlassFish
27. EJB Server JBoss 4.2.1
28. EJB Server resin 3.1.5
29. ERP CRM Financial
30. ESB
31. Forum
32. GIS
33. Graphic Library
34. Groupware
35. HTML Parser
36. IDE
37. IDE Eclipse
38. IDE Netbeans
39. Installer
40. Internationalization Localization
41. Inversion of Control
42. Issue Tracking
43. J2EE
44. JBoss
45. JMS
46. JMX
47. Library
48. Mail Clients
49. Net
50. Parser
51. PDF
52. Portal
53. Profiler
54. Project Management
55. Report
56. RSS RDF
57. Rule Engine
58. Science
59. Scripting
60. Search Engine
61. Security
62. Sevlet Container
63. Source Control
64. Swing Library
65. Template Engine
66. Test Coverage
67. Testing
68. UML
69. Web Crawler
70. Web Framework
71. Web Mail
72. Web Server
73. Web Services
74. Web Services apache cxf 2.0.1
75. Web Services AXIS2
76. Wiki Engine
77. Workflow Engines
78. XML
79. XML UI
Java
Java Tutorial
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorials
Maya Tutorials
Flash Tutorials
3ds-Max Tutorials
Illustrator Tutorials
GIMP Tutorials
C# / C Sharp
C# / CSharp Tutorial
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
SQL Server / T-SQL Tutorial
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
Java Source Code / Java Documentation » Library » Apache commons scxml 0.6 src » org.apache.commons.scxml 
Source Cross Referenced  Class Diagram Java Document (Java Doc) 


001:        /*
002:         * Licensed to the Apache Software Foundation (ASF) under one or more
003:         * contributor license agreements.  See the NOTICE file distributed with
004:         * this work for additional information regarding copyright ownership.
005:         * The ASF licenses this file to You under the Apache License, Version 2.0
006:         * (the "License"); you may not use this file except in compliance with
007:         * the License.  You may obtain a copy of the License at
008:         *
009:         *     http://www.apache.org/licenses/LICENSE-2.0
010:         *
011:         * Unless required by applicable law or agreed to in writing, software
012:         * distributed under the License is distributed on an "AS IS" BASIS,
013:         * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014:         * See the License for the specific language governing permissions and
015:         * limitations under the License.
016:         */
017:        package org.apache.commons.scxml;
018:
019:        import java.io.Serializable;
020:        import java.util.ArrayList;
021:        import java.util.Arrays;
022:        import java.util.HashMap;
023:        import java.util.Iterator;
024:        import java.util.List;
025:        import java.util.Map;
026:
027:        import org.apache.commons.logging.Log;
028:        import org.apache.commons.logging.LogFactory;
029:        import org.apache.commons.scxml.model.Datamodel;
030:        import org.apache.commons.scxml.model.History;
031:        import org.apache.commons.scxml.model.ModelException;
032:        import org.apache.commons.scxml.model.SCXML;
033:        import org.apache.commons.scxml.model.State;
034:        import org.apache.commons.scxml.model.Transition;
035:        import org.apache.commons.scxml.model.TransitionTarget;
036:        import org.apache.commons.scxml.semantics.SCXMLSemanticsImpl;
037:
038:        /**
039:         * <p>The SCXML &quot;engine&quot; that executes SCXML documents. The
040:         * particular semantics used by this engine for executing the SCXML are
041:         * encapsulated in the SCXMLSemantics implementation that it uses.</p>
042:         *
043:         * <p>The default implementation is
044:         * <code>org.apache.commons.scxml.semantics.SCXMLSemanticsImpl</code></p>
045:         *
046:         * @see SCXMLSemantics
047:         */
048:        public class SCXMLExecutor implements  Serializable {
049:
050:            /**
051:             * Serial version UID.
052:             */
053:            private static final long serialVersionUID = 1L;
054:
055:            /**
056:             * The Logger for the SCXMLExecutor.
057:             */
058:            private Log log = LogFactory.getLog(SCXMLExecutor.class);
059:
060:            /**
061:             * The stateMachine being executed.
062:             */
063:            private SCXML stateMachine;
064:
065:            /**
066:             * The current status of the stateMachine.
067:             */
068:            private Status currentStatus;
069:
070:            /**
071:             * The event dispatcher to interface with external documents etc.
072:             */
073:            private EventDispatcher eventdispatcher;
074:
075:            /**
076:             * The environment specific error reporter.
077:             */
078:            private ErrorReporter errorReporter = null;
079:
080:            /**
081:             * Run-to-completion.
082:             */
083:            private boolean super Step = true;
084:
085:            /**
086:             *  Interpretation semantics.
087:             */
088:            private SCXMLSemantics semantics;
089:
090:            /**
091:             * The SCInstance.
092:             */
093:            private SCInstance scInstance;
094:
095:            /**
096:             * The worker method.
097:             * Re-evaluates current status whenever any events are triggered.
098:             *
099:             * @param evts
100:             *            an array of external events which triggered during the last
101:             *            time quantum
102:             * @throws ModelException in case there is a fatal SCXML object
103:             *            model problem.
104:             */
105:            public synchronized void triggerEvents(final TriggerEvent[] evts)
106:                    throws ModelException {
107:                // Set event data, saving old values
108:                Object[] oldData = setEventData(evts);
109:
110:                // Forward events (external only) to any existing invokes,
111:                // and finalize processing
112:                semantics.processInvokes(evts, errorReporter, scInstance);
113:
114:                List evs = new ArrayList(Arrays.asList(evts));
115:                Step step = null;
116:
117:                do {
118:                    // CreateStep
119:                    step = new Step(evs, currentStatus);
120:                    // EnumerateReachableTransitions
121:                    semantics.enumerateReachableTransitions(stateMachine, step,
122:                            errorReporter);
123:                    // FilterTransitionSet
124:                    semantics.filterTransitionsSet(step, eventdispatcher,
125:                            errorReporter, scInstance);
126:                    // FollowTransitions
127:                    semantics
128:                            .followTransitions(step, errorReporter, scInstance);
129:                    // UpdateHistoryStates
130:                    semantics.updateHistoryStates(step, errorReporter,
131:                            scInstance);
132:                    // ExecuteActions
133:                    semantics.executeActions(step, stateMachine,
134:                            eventdispatcher, errorReporter, scInstance);
135:                    // AssignCurrentStatus
136:                    updateStatus(step);
137:                    // ***Cleanup external events if superStep
138:                    if (super Step) {
139:                        evs.clear();
140:                    }
141:                } while (super Step && currentStatus.getEvents().size() > 0);
142:
143:                // InitiateInvokes only after state machine has stabilized
144:                semantics.initiateInvokes(step, errorReporter, scInstance);
145:
146:                // Restore event data
147:                restoreEventData(oldData);
148:                logState();
149:            }
150:
151:            /**
152:             * Convenience method when only one event needs to be triggered.
153:             *
154:             * @param evt
155:             *            the external events which triggered during the last
156:             *            time quantum
157:             * @throws ModelException in case there is a fatal SCXML object
158:             *            model problem.
159:             */
160:            public void triggerEvent(final TriggerEvent evt)
161:                    throws ModelException {
162:                triggerEvents(new TriggerEvent[] { evt });
163:            }
164:
165:            /**
166:             * Constructor.
167:             *
168:             * @param expEvaluator The expression evaluator
169:             * @param evtDisp The event dispatcher
170:             * @param errRep The error reporter
171:             */
172:            public SCXMLExecutor(final Evaluator expEvaluator,
173:                    final EventDispatcher evtDisp, final ErrorReporter errRep) {
174:                this (expEvaluator, evtDisp, errRep, null);
175:            }
176:
177:            /**
178:             * Convenience constructor.
179:             */
180:            public SCXMLExecutor() {
181:                this (null, null, null, null);
182:            }
183:
184:            /**
185:             * Constructor.
186:             *
187:             * @param expEvaluator The expression evaluator
188:             * @param evtDisp The event dispatcher
189:             * @param errRep The error reporter
190:             * @param semantics The SCXML semantics
191:             */
192:            public SCXMLExecutor(final Evaluator expEvaluator,
193:                    final EventDispatcher evtDisp, final ErrorReporter errRep,
194:                    final SCXMLSemantics semantics) {
195:                this .eventdispatcher = evtDisp;
196:                this .errorReporter = errRep;
197:                this .currentStatus = new Status();
198:                this .stateMachine = null;
199:                if (semantics == null) {
200:                    // Use default semantics, if none provided
201:                    this .semantics = new SCXMLSemanticsImpl();
202:                } else {
203:                    this .semantics = semantics;
204:                }
205:                this .scInstance = new SCInstance(this );
206:                this .scInstance.setEvaluator(expEvaluator);
207:            }
208:
209:            /**
210:             * Clear all state and begin from &quot;initialstate&quot; indicated
211:             * on root SCXML element.
212:             *
213:             * @throws ModelException in case there is a fatal SCXML object
214:             *         model problem.
215:             */
216:            public synchronized void reset() throws ModelException {
217:                // Reset all variable contexts
218:                Context rootCtx = scInstance.getRootContext();
219:                // Clone root datamodel
220:                if (stateMachine == null) {
221:                    log.error(ERR_NO_STATE_MACHINE);
222:                    throw new ModelException(ERR_NO_STATE_MACHINE);
223:                } else {
224:                    Datamodel rootdm = stateMachine.getDatamodel();
225:                    SCXMLHelper.cloneDatamodel(rootdm, rootCtx, scInstance
226:                            .getEvaluator(), log);
227:                }
228:                // all states and parallels, only states have variable contexts
229:                for (Iterator i = stateMachine.getTargets().values().iterator(); i
230:                        .hasNext();) {
231:                    TransitionTarget tt = (TransitionTarget) i.next();
232:                    if (tt instanceof  State) {
233:                        Context context = scInstance.lookupContext(tt);
234:                        if (context != null) {
235:                            context.reset();
236:                            Datamodel dm = tt.getDatamodel();
237:                            if (dm != null) {
238:                                SCXMLHelper.cloneDatamodel(dm, context,
239:                                        scInstance.getEvaluator(), log);
240:                            }
241:                        }
242:                    } else if (tt instanceof  History) {
243:                        scInstance.reset((History) tt);
244:                    }
245:                }
246:                // CreateEmptyStatus
247:                currentStatus = new Status();
248:                Step step = new Step(null, currentStatus);
249:                // DetermineInitialStates
250:                semantics.determineInitialStates(stateMachine, step
251:                        .getAfterStatus().getStates(), step.getEntryList(),
252:                        errorReporter, scInstance);
253:                // ExecuteActions
254:                semantics.executeActions(step, stateMachine, eventdispatcher,
255:                        errorReporter, scInstance);
256:                // AssignCurrentStatus
257:                updateStatus(step);
258:                // Execute Immediate Transitions
259:                if (super Step && currentStatus.getEvents().size() > 0) {
260:                    this .triggerEvents(new TriggerEvent[0]);
261:                } else {
262:                    // InitiateInvokes only after state machine has stabilized
263:                    semantics.initiateInvokes(step, errorReporter, scInstance);
264:                    logState();
265:                }
266:            }
267:
268:            /**
269:             * Get the current status.
270:             *
271:             * @return The current Status
272:             */
273:            public synchronized Status getCurrentStatus() {
274:                return currentStatus;
275:            }
276:
277:            /**
278:             * Set the expression evaluator.
279:             *
280:             * @param evaluator The evaluator to set.
281:             */
282:            public void setEvaluator(final Evaluator evaluator) {
283:                this .scInstance.setEvaluator(evaluator);
284:            }
285:
286:            /**
287:             * Get the expression evaluator in use.
288:             *
289:             * @return Evaluator The evaluator in use.
290:             */
291:            public Evaluator getEvaluator() {
292:                return scInstance.getEvaluator();
293:            }
294:
295:            /**
296:             * Set the root context for this execution.
297:             *
298:             * @param rootContext The Context that ties to the host environment.
299:             */
300:            public void setRootContext(final Context rootContext) {
301:                this .scInstance.setRootContext(rootContext);
302:            }
303:
304:            /**
305:             * Get the root context for this execution.
306:             *
307:             * @return Context The root context.
308:             */
309:            public Context getRootContext() {
310:                return scInstance.getRootContext();
311:            }
312:
313:            /**
314:             * Get the state machine that is being executed.
315:             *
316:             * @return Returns the stateMachine.
317:             */
318:            public SCXML getStateMachine() {
319:                return stateMachine;
320:            }
321:
322:            /**
323:             * Set the state machine to be executed.
324:             *
325:             * @param stateMachine The stateMachine to set.
326:             */
327:            public void setStateMachine(final SCXML stateMachine) {
328:                // NormalizeStateMachine
329:                SCXML sm = semantics.normalizeStateMachine(stateMachine,
330:                        errorReporter);
331:                // StoreStateMachine
332:                this .stateMachine = sm;
333:            }
334:
335:            /**
336:             * Initiate state machine execution.
337:             *
338:             * @throws ModelException in case there is a fatal SCXML object
339:             *  model problem.
340:             */
341:            public void go() throws ModelException {
342:                // same as reset
343:                this .reset();
344:            }
345:
346:            /**
347:             * Get the environment specific error reporter.
348:             *
349:             * @return Returns the errorReporter.
350:             */
351:            public ErrorReporter getErrorReporter() {
352:                return errorReporter;
353:            }
354:
355:            /**
356:             * Set the environment specific error reporter.
357:             *
358:             * @param errorReporter The errorReporter to set.
359:             */
360:            public void setErrorReporter(final ErrorReporter errorReporter) {
361:                this .errorReporter = errorReporter;
362:            }
363:
364:            /**
365:             * Get the event dispatcher.
366:             *
367:             * @return Returns the eventdispatcher.
368:             */
369:            public EventDispatcher getEventdispatcher() {
370:                return eventdispatcher;
371:            }
372:
373:            /**
374:             * Set the event dispatcher.
375:             *
376:             * @param eventdispatcher The eventdispatcher to set.
377:             */
378:            public void setEventdispatcher(final EventDispatcher eventdispatcher) {
379:                this .eventdispatcher = eventdispatcher;
380:            }
381:
382:            /**
383:             * Use &quot;super-step&quot;, default is <code>true</code>
384:             * (that is, run-to-completion is default).
385:             *
386:             * @return Returns the superStep property.
387:             * @see #setSuperStep(boolean)
388:             */
389:            public boolean isSuperStep() {
390:                return super Step;
391:            }
392:
393:            /**
394:             * Set the super step.
395:             *
396:             * @param superStep
397:             * if true, the internal derived events are also processed
398:             *    (run-to-completion);
399:             * if false, the internal derived events are stored in the
400:             * CurrentStatus property and processed within the next
401:             * triggerEvents() invocation, also the immediate (empty event) transitions
402:             * are deferred until the next step
403:             */
404:            public void setSuperStep(final boolean super Step) {
405:                this .super Step = super Step;
406:            }
407:
408:            /**
409:             * Add a listener to the document root.
410:             *
411:             * @param scxml The document root to attach listener to.
412:             * @param listener The SCXMLListener.
413:             */
414:            public void addListener(final SCXML scxml,
415:                    final SCXMLListener listener) {
416:                Object observable = scxml;
417:                scInstance.getNotificationRegistry().addListener(observable,
418:                        listener);
419:            }
420:
421:            /**
422:             * Remove this listener from the document root.
423:             *
424:             * @param scxml The document root.
425:             * @param listener The SCXMLListener to be removed.
426:             */
427:            public void removeListener(final SCXML scxml,
428:                    final SCXMLListener listener) {
429:                Object observable = scxml;
430:                scInstance.getNotificationRegistry().removeListener(observable,
431:                        listener);
432:            }
433:
434:            /**
435:             * Add a listener to this transition target.
436:             *
437:             * @param transitionTarget The <code>TransitionTarget</code> to
438:             *                         attach listener to.
439:             * @param listener The SCXMLListener.
440:             */
441:            public void addListener(final TransitionTarget transitionTarget,
442:                    final SCXMLListener listener) {
443:                Object observable = transitionTarget;
444:                scInstance.getNotificationRegistry().addListener(observable,
445:                        listener);
446:            }
447:
448:            /**
449:             * Remove this listener for this transition target.
450:             *
451:             * @param transitionTarget The <code>TransitionTarget</code>.
452:             * @param listener The SCXMLListener to be removed.
453:             */
454:            public void removeListener(final TransitionTarget transitionTarget,
455:                    final SCXMLListener listener) {
456:                Object observable = transitionTarget;
457:                scInstance.getNotificationRegistry().removeListener(observable,
458:                        listener);
459:            }
460:
461:            /**
462:             * Add a listener to this transition.
463:             *
464:             * @param transition The <code>Transition</code> to attach listener to.
465:             * @param listener The SCXMLListener.
466:             */
467:            public void addListener(final Transition transition,
468:                    final SCXMLListener listener) {
469:                Object observable = transition;
470:                scInstance.getNotificationRegistry().addListener(observable,
471:                        listener);
472:            }
473:
474:            /**
475:             * Remove this listener for this transition.
476:             *
477:             * @param transition The <code>Transition</code>.
478:             * @param listener The SCXMLListener to be removed.
479:             */
480:            public void removeListener(final Transition transition,
481:                    final SCXMLListener listener) {
482:                Object observable = transition;
483:                scInstance.getNotificationRegistry().removeListener(observable,
484:                        listener);
485:            }
486:
487:            /**
488:             * Register an <code>Invoker</code> for this target type.
489:             *
490:             * @param targettype The target type (specified by "targettype"
491:             *                   attribute of &lt;invoke&gt; tag).
492:             * @param invokerClass The <code>Invoker</code> <code>Class</code>.
493:             */
494:            public void registerInvokerClass(final String targettype,
495:                    final Class invokerClass) {
496:                scInstance.registerInvokerClass(targettype, invokerClass);
497:            }
498:
499:            /**
500:             * Remove the <code>Invoker</code> registered for this target
501:             * type (if there is one registered).
502:             *
503:             * @param targettype The target type (specified by "targettype"
504:             *                   attribute of &lt;invoke&gt; tag).
505:             */
506:            public void unregisterInvokerClass(final String targettype) {
507:                scInstance.unregisterInvokerClass(targettype);
508:            }
509:
510:            /**
511:             * Get the state chart instance for this executor.
512:             *
513:             * @return The SCInstance for this executor.
514:             */
515:            SCInstance getSCInstance() {
516:                return scInstance;
517:            }
518:
519:            /**
520:             * Log the current set of active states.
521:             */
522:            private void logState() {
523:                if (log.isInfoEnabled()) {
524:                    Iterator si = currentStatus.getStates().iterator();
525:                    StringBuffer sb = new StringBuffer("Current States: [");
526:                    while (si.hasNext()) {
527:                        State s = (State) si.next();
528:                        sb.append(s.getId());
529:                        if (si.hasNext()) {
530:                            sb.append(", ");
531:                        }
532:                    }
533:                    sb.append(']');
534:                    log.info(sb.toString());
535:                }
536:            }
537:
538:            /**
539:             * @param step The most recent Step
540:             */
541:            private void updateStatus(final Step step) {
542:                currentStatus = step.getAfterStatus();
543:                scInstance.getRootContext().setLocal(
544:                        "_ALL_STATES",
545:                        SCXMLHelper.getAncestorClosure(currentStatus
546:                                .getStates(), null));
547:            }
548:
549:            /**
550:             * @param evts The events being triggered.
551:             * @return Object[] Previous values.
552:             */
553:            private Object[] setEventData(final TriggerEvent[] evts) {
554:                Context rootCtx = scInstance.getRootContext();
555:                Object[] oldData = { rootCtx.get(EVENT_DATA),
556:                        rootCtx.get(EVENT_DATA_MAP) };
557:                Object eventData = null;
558:                Map payloadMap = new HashMap();
559:                int len = evts.length;
560:                for (int i = 0; i < len; i++) {
561:                    TriggerEvent te = evts[i];
562:                    payloadMap.put(te.getName(), te.getPayload());
563:                }
564:                if (len == 1) {
565:                    // we have only one event
566:                    eventData = evts[0].getPayload();
567:                }
568:                rootCtx.setLocal(EVENT_DATA, eventData);
569:                rootCtx.setLocal(EVENT_DATA_MAP, payloadMap);
570:                return oldData;
571:            }
572:
573:            /**
574:             * @param oldData The old values to restore to.
575:             */
576:            private void restoreEventData(final Object[] oldData) {
577:                scInstance.getRootContext().setLocal(EVENT_DATA, oldData[0]);
578:                scInstance.getRootContext()
579:                        .setLocal(EVENT_DATA_MAP, oldData[1]);
580:            }
581:
582:            /**
583:             * The special variable for storing single event data / payload.
584:             */
585:            private static final String EVENT_DATA = "_eventdata";
586:
587:            /**
588:             * The special variable for storing event data / payload,
589:             * when multiple events are triggered, keyed by event name.
590:             */
591:            private static final String EVENT_DATA_MAP = "_eventdatamap";
592:
593:            /**
594:             * SCXMLExecutor put into motion without setting a model (state machine).
595:             */
596:            private static final String ERR_NO_STATE_MACHINE = "SCXMLExecutor: State machine not set";
597:
598:        }
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.