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17
18
19
20 package org.apache.lenya.workflow.impl;
21
22 import java.util.ArrayList  ;
23 import java.util.Arrays ;
24 import java.util.HashMap ;
25 import java.util.HashSet ;
26 import java.util.Iterator ;
27 import java.util.List ;
28 import java.util.Map ;
29 import java.util.Set ;
30
31 import org.apache.lenya.workflow.Action;
32 import org.apache.lenya.workflow.BooleanVariable;
33 import org.apache.lenya.workflow.BooleanVariableInstance;
34 import org.apache.lenya.workflow.Event;
35 import org.apache.lenya.workflow.Situation;
36 import org.apache.lenya.workflow.State;
37 import org.apache.lenya.workflow.Transition;
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.log4j.Category;
43
44
45
48 public abstract class WorkflowInstanceImpl implements WorkflowInstance {
49
50 private static final Category log = Category.getInstance(WorkflowInstanceImpl.class);
51
52
55 protected WorkflowInstanceImpl() {
56 }
57
58 private WorkflowImpl workflow;
59
60
64 public Workflow getWorkflow() {
65 return getWorkflowImpl();
66 }
67
68
72 protected WorkflowImpl getWorkflowImpl() {
73 return workflow;
74 }
75
76
81 public Event[] getExecutableEvents(Situation situation) throws WorkflowException {
82
83 if (log.isDebugEnabled()) {
84 log.debug("Resolving executable events");
85 }
86
87 Transition[] transitions = getWorkflow().getLeavingTransitions(getCurrentState());
88 Set executableEvents = new HashSet ();
89
90 for (int i = 0; i < transitions.length; i++) {
91 if (transitions[i].canFire(situation, this)) {
92 executableEvents.add(transitions[i].getEvent());
93 if (log.isDebugEnabled()) {
94 log.debug(" [" + transitions[i].getEvent() + "] can fire.");
95 }
96 }
97 else {
98 if (log.isDebugEnabled()) {
99 log.debug(" [" + transitions[i].getEvent() + "] can not fire.");
100 }
101 }
102 }
103
104 if (log.isDebugEnabled()) {
105 log.debug(" Resolving executable events completed.");
106 }
107
108 return (Event[]) executableEvents.toArray(new Event[executableEvents.size()]);
109 }
110
111
116 public void invoke(Situation situation, Event event)
117 throws WorkflowException {
118 if (!Arrays.asList(getExecutableEvents(situation)).contains(event)) {
119 throw new WorkflowException("The event '" + event +
120 "' cannot be invoked in the situation '" + situation + "'.");
121 }
122
123 fire(getNextTransition(event));
124
125 for (Iterator iter = listeners.iterator(); iter.hasNext();) {
126 WorkflowListener listener = (WorkflowListener) iter.next();
127 listener.transitionFired(this, situation, event);
128 }
129 }
130
131
137 protected TransitionImpl getNextTransition(Event event) throws WorkflowException {
138 TransitionImpl nextTransition = null;
139 Transition[] transitions = getWorkflow().getLeavingTransitions(getCurrentState());
140
141 for (int i = 0; i < transitions.length; i++) {
142 if (transitions[i].getEvent().equals(event)) {
143
144 if (nextTransition != null) {
145 throw new WorkflowException("More than one transition found for event [" + event + "]!");
146 }
147
148 nextTransition = (TransitionImpl) transitions[i];
149 }
150 }
151
152 if (nextTransition == null) {
153 throw new WorkflowException("No transition found for event [" + event + "]!");
154 }
155
156 return nextTransition;
157 }
158
159
164 protected void fire(TransitionImpl transition) throws WorkflowException {
165 Action[] actions = transition.getActions();
166
167 for (int i = 0; i < actions.length; i++) {
168 actions[i].execute(this);
169 }
170
171 setCurrentState(transition.getDestination());
172 }
173
174 private State currentState;
175
176
180 protected void setCurrentState(State state) {
181 this.currentState = state;
182 }
183
184
187 public State getCurrentState() {
188 return currentState;
189 }
190
191
195 protected void setWorkflow(WorkflowImpl workflow) {
196 this.workflow = workflow;
197 setCurrentState(getWorkflow().getInitialState());
198 initVariableInstances();
199 }
200
201
206 protected void setWorkflow(String workflowName) throws WorkflowException {
207 setWorkflow(getWorkflow(workflowName));
208 }
209
210
216 protected abstract WorkflowImpl getWorkflow(String workflowName)
217 throws WorkflowException;
218
219
225 protected State getState(String id) throws WorkflowException {
226 return getWorkflowImpl().getState(id);
227 }
228
229 private Map variableInstances = new HashMap ();
230
231
234 protected void initVariableInstances() {
235 variableInstances.clear();
236
237 BooleanVariable[] variables = getWorkflowImpl().getVariables();
238
239 for (int i = 0; i < variables.length; i++) {
240 BooleanVariableInstance instance = new BooleanVariableInstanceImpl();
241 instance.setValue(variables[i].getInitialValue());
242 variableInstances.put(variables[i], instance);
243 }
244 }
245
246
252 protected BooleanVariableInstance getVariableInstance(BooleanVariable variable)
253 throws WorkflowException {
254 if (!variableInstances.containsKey(variable)) {
255 throw new WorkflowException("No instance for variable '" + variable.getName() + "'!");
256 }
257
258 return (BooleanVariableInstance) variableInstances.get(variable);
259 }
260
261
264 public boolean getValue(String variableName) throws WorkflowException {
265 BooleanVariable variable = getWorkflowImpl().getVariable(variableName);
266 BooleanVariableInstance instance = getVariableInstance(variable);
267
268 return instance.getValue();
269 }
270
271
277 protected void setValue(String variableName, boolean value)
278 throws WorkflowException {
279 BooleanVariable variable = getWorkflowImpl().getVariable(variableName);
280 BooleanVariableInstance instance = getVariableInstance(variable);
281 instance.setValue(value);
282 }
283
284 private List listeners = new ArrayList ();
285
286
289 public void addWorkflowListener(WorkflowListener listener) {
290 if (!listeners.contains(listener)) {
291 listeners.add(listener);
292 }
293 }
294
295
298 public void removeWorkflowListener(WorkflowListener listener) {
299 listeners.remove(listener);
300 }
301
302
305 public boolean isSynchronized(Event event) throws WorkflowException {
306 Transition nextTransition = getNextTransition(event);
307 return nextTransition.isSynchronized();
308 }
309
310 }
311 |
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