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1
17
18
19
20 package org.apache.lenya.workflow.impl;
21
22 import java.io.File  ;
23 import java.io.FileInputStream ;
24 import java.io.FileOutputStream ;
25 import java.io.IOException ;
26 import java.nio.channels.FileChannel ;
27 import java.text.SimpleDateFormat ;
28 import java.util.ArrayList ;
29 import java.util.Date ;
30 import java.util.List ;
31
32 import javax.xml.transform.TransformerException ;
33
34 import org.apache.lenya.workflow.BooleanVariable;
35 import org.apache.lenya.workflow.Event;
36 import org.apache.lenya.workflow.Situation;
37 import org.apache.lenya.workflow.State;
38 import org.apache.lenya.workflow.Workflow;
39 import org.apache.lenya.workflow.WorkflowException;
40 import org.apache.lenya.workflow.WorkflowInstance;
41 import org.apache.lenya.workflow.WorkflowListener;
42 import org.apache.lenya.xml.DocumentHelper;
43 import org.apache.lenya.xml.NamespaceHelper;
44 import org.apache.xpath.XPathAPI;
45 import org.w3c.dom.Document ;
46 import org.w3c.dom.Element ;
47
48
58 public abstract class History implements WorkflowListener {
59 public static final String WORKFLOW_ATTRIBUTE = "workflow";
60 public static final String HISTORY_ELEMENT = "history";
61 public static final String VERSION_ELEMENT = "version";
62 public static final String STATE_ATTRIBUTE = "state";
63 public static final String EVENT_ATTRIBUTE = "event";
64 public static final String VARIABLE_ELEMENT = "variable";
65 public static final String NAME_ATTRIBUTE = "name";
66 public static final String VALUE_ATTRIBUTE = "value";
67 public static final String DATE_ATTRIBUTE = "date";
68
69
75 public void initialize(String workflowId, Situation situation) throws WorkflowException {
76 try {
77 File file = getHistoryFile();
78 file.getParentFile().mkdirs();
79 file.createNewFile();
80
81 NamespaceHelper helper = new NamespaceHelper(Workflow.NAMESPACE,
82 Workflow.DEFAULT_PREFIX, HISTORY_ELEMENT);
83
84 Element historyElement = helper.getDocument().getDocumentElement();
85 historyElement.setAttribute(WORKFLOW_ATTRIBUTE, workflowId);
86
87 Element initialVersionElement = createInitialVersionElement(helper, situation,
88 workflowId);
89 historyElement.appendChild(initialVersionElement);
90
91 DocumentHelper.writeDocument(helper.getDocument(), file);
92 } catch (Exception e) {
93 throw new WorkflowException(e);
94 }
95 }
96
97
100 protected History() {
101 }
102
103 private WorkflowInstanceImpl instance = null;
104
105
110 protected NamespaceHelper getNamespaceHelper() throws WorkflowException {
111 NamespaceHelper helper;
112 try {
113 Document document = DocumentHelper.readDocument(getHistoryFile());
114 helper = new NamespaceHelper(Workflow.NAMESPACE, Workflow.DEFAULT_PREFIX, document);
115 } catch (Exception e) {
116 throw new WorkflowException(e);
117 }
118 return helper;
119 }
120
121
126 protected String getWorkflowId() throws WorkflowException {
127 return getWorkflowId(getNamespaceHelper());
128 }
129
130
136 protected String getWorkflowId(NamespaceHelper helper) throws WorkflowException {
137 String workflowId = helper.getDocument().getDocumentElement().getAttribute(
138 WORKFLOW_ATTRIBUTE);
139 if (workflowId == null) {
140 throw new WorkflowException("The attribute '" + WORKFLOW_ATTRIBUTE + "' is missing!");
141 }
142 if ("".equals(workflowId)) {
143 throw new WorkflowException("The workflow ID must not be empty!");
144 }
145 return workflowId;
146 }
147
148
153 public WorkflowInstanceImpl getInstance() throws WorkflowException {
154 if (this.instance == null) {
155 if (!isInitialized()) {
156 throw new WorkflowException(
157 "The workflow history has not been initialized: The file ["
158 + getHistoryFile() + "] is missing.");
159 }
160
161 WorkflowInstanceImpl instance = createInstance();
162 NamespaceHelper helper = getNamespaceHelper();
163
164 String workflowId = getWorkflowId(helper);
165 if (null == workflowId) {
166 throw new WorkflowException("No workflow attribute set in history document!");
167 }
168
169 instance.setWorkflow(workflowId);
170
171 restoreState(instance, helper);
172 restoreVariables(instance, helper);
173
174 instance.addWorkflowListener(this);
175 setInstance(instance);
176 }
177
178 return instance;
179 }
180
181
185 public boolean isInitialized() {
186 return getHistoryFile().exists();
187 }
188
189
193 protected abstract File getHistoryFile();
194
195
200 protected abstract WorkflowInstanceImpl createInstance() throws WorkflowException;
201
202
210 protected Element createInitialVersionElement(NamespaceHelper helper, Situation situation,
211 String workflowId) throws WorkflowException {
212 Element versionElement = createVersionElement(helper, situation);
213
214 WorkflowInstanceImpl instance = createInstance();
215 instance.setWorkflow(workflowId);
216
217 StateImpl initialState = (StateImpl) instance.getWorkflow().getInitialState();
218 versionElement.setAttribute(STATE_ATTRIBUTE, initialState.getId());
219
220 return versionElement;
221 }
222
223
231 protected Element createVersionElement(NamespaceHelper helper, StateImpl state,
232 Situation situation, Event event) {
233 Element versionElement = createVersionElement(helper, situation);
234 versionElement.setAttribute(STATE_ATTRIBUTE, state.getId());
235 versionElement.setAttribute(EVENT_ATTRIBUTE, event.getName());
236 return versionElement;
237 }
238
239
245 protected Element createVersionElement(NamespaceHelper helper, Situation situation) {
246 Element versionElement = helper.createElement(VERSION_ELEMENT);
247 Date now = new Date ();
248 SimpleDateFormat format = new SimpleDateFormat ("yyyy-MM-dd HH:mm:ss");
249 String dateString = format.format(now);
250 versionElement.setAttribute(DATE_ATTRIBUTE, dateString);
251 return versionElement;
252 }
253
254
263 public void transitionFired(WorkflowInstance instance, Situation situation, Event event)
264 throws WorkflowException {
265 try {
266 org.w3c.dom.Document xmlDocument = DocumentHelper.readDocument(getHistoryFile());
267 Element root = xmlDocument.getDocumentElement();
268
269 NamespaceHelper helper = new NamespaceHelper(Workflow.NAMESPACE,
270 Workflow.DEFAULT_PREFIX, xmlDocument);
271
272 Element versionElement = createVersionElement(helper, (StateImpl) instance
273 .getCurrentState(), situation, event);
274
275 root.appendChild(versionElement);
276
277 saveVariables(helper);
278
279 DocumentHelper.writeDocument(xmlDocument, getHistoryFile());
280 } catch (Exception e) {
281 throw new WorkflowException(e);
282 }
283 }
284
285
289 public void setInstance(WorkflowInstanceImpl impl) {
290 instance = impl;
291 }
292
293
298 protected void saveVariables(NamespaceHelper helper) throws WorkflowException {
299 Element parent = helper.getDocument().getDocumentElement();
300 BooleanVariable[] variables = getInstance().getWorkflowImpl().getVariables();
301
302 for (int i = 0; i < variables.length; i++) {
303 String name = variables[i].getName();
304 boolean value = getInstance().getValue(name);
305
306 try {
307 Element element = (Element ) XPathAPI.selectSingleNode(parent, "*[local-name() = '"
308 + VARIABLE_ELEMENT + "']" + "[@" + NAME_ATTRIBUTE + " = '" + name + "']");
309
310 if (element == null) {
311 element = helper.createElement(VARIABLE_ELEMENT);
312 element.setAttribute(NAME_ATTRIBUTE, name);
313 parent.appendChild(element);
314 }
315
316 element.setAttribute(VALUE_ATTRIBUTE, Boolean.toString(value));
317 } catch (TransformerException e) {
318 throw new WorkflowException(e);
319 }
320 }
321 }
322
323
329 protected void restoreVariables(WorkflowInstanceImpl instance, NamespaceHelper helper)
330 throws WorkflowException {
331 Element parent = helper.getDocument().getDocumentElement();
332
333 Element [] variableElements = helper.getChildren(parent, VARIABLE_ELEMENT);
334
335 for (int i = 0; i < variableElements.length; i++) {
336 String name = variableElements[i].getAttribute(NAME_ATTRIBUTE);
337 String value = variableElements[i].getAttribute(VALUE_ATTRIBUTE);
338 instance.setValue(name, Boolean.valueOf(value).booleanValue());
339 }
340 }
341
342
348 protected void restoreState(WorkflowInstanceImpl instance, NamespaceHelper helper)
349 throws WorkflowException {
350 State state;
351 Element [] versionElements = helper.getChildren(helper.getDocument().getDocumentElement(),
352 VERSION_ELEMENT);
353
354 if (versionElements.length > 0) {
355 Element lastElement = versionElements[versionElements.length - 1];
356 String stateId = lastElement.getAttribute(STATE_ATTRIBUTE);
357 state = instance.getWorkflowImpl().getState(stateId);
358 } else {
359 state = instance.getWorkflow().getInitialState();
360 }
361
362 instance.setCurrentState(state);
363 }
364
365
370 protected void move(File newFile) throws WorkflowException {
371
372 FileInputStream sourceStream = null;
373 FileOutputStream destinationStream = null;
374 FileChannel sourceChannel = null;
375 FileChannel destinationChannel = null;
376 try {
377 newFile.getParentFile().mkdirs();
378 newFile.createNewFile();
379 File historyFile = getHistoryFile();
380
381 sourceStream = new FileInputStream (historyFile);
382 sourceChannel = sourceStream.getChannel();
383
384 destinationStream = new FileOutputStream (newFile);
385 destinationChannel = destinationStream.getChannel();
386
387 destinationChannel.transferFrom(sourceChannel, 0, sourceChannel.size());
388 sourceStream.close();
389 destinationStream.close();
390 File directory = historyFile.getParentFile();
391 boolean deleted = historyFile.delete();
392 if (!deleted) {
393 throw new WorkflowException("The old history file could not be deleted!");
394 }
395 if (directory.exists() && directory.isDirectory() && directory.listFiles().length == 0) {
396 directory.delete();
397 }
398 } catch (IOException e) {
399 throw new WorkflowException(e);
400 } finally {
401 try {
402 if (sourceStream != null)
403 sourceStream.close();
404 if (destinationStream != null)
405 destinationStream.close();
406 } catch (IOException e) {
407 throw new WorkflowException(e);
408 }
409 }
410 }
411
412
419 protected Version restoreVersion(NamespaceHelper helper, Element element)
420 throws WorkflowException {
421 if (!element.getLocalName().equals(VERSION_ELEMENT)) {
422 throw new WorkflowException("Invalid history XML!");
423 }
424
425 Event event = null;
426 String eventId = element.getAttribute(EVENT_ATTRIBUTE);
427 if (eventId != null && !"".equals(eventId)) {
428 event = getInstance().getWorkflowImpl().getEvent(eventId);
429 }
430
431 String stateId = element.getAttribute(STATE_ATTRIBUTE);
432 State state = getInstance().getWorkflowImpl().getState(stateId);
433
434 Version version = new Version(event, state);
435 return version;
436 }
437
438
443 public Version[] getVersions() throws WorkflowException {
444 List versions = new ArrayList ();
445
446 NamespaceHelper helper = getNamespaceHelper();
447 Element documentElement = helper.getDocument().getDocumentElement();
448 Element [] versionElements = getNamespaceHelper().getChildren(documentElement,
449 VERSION_ELEMENT);
450
451 for (int i = 0; i < versionElements.length; i++) {
452 Version version = restoreVersion(helper, versionElements[i]);
453 versions.add(version);
454 }
455 return (Version[]) versions.toArray(new Version[versions.size()]);
456 }
457
458
462 public void delete() throws WorkflowException {
463 System.out.println("Deleting file [" + getHistoryFile() + "]");
464 if (!isInitialized()) {
465 throw new WorkflowException("The workflow history is not initialized!");
466 }
467
468 boolean deleted = getHistoryFile().delete();
469
470 if (!deleted) {
471 throw new WorkflowException("The workflow history could not be deleted!");
472 }
473
474 }
475
476 } |
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