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1 package org.jbpm.graph.node;
2
3 import java.util.ArrayList  ;
4 import java.util.HashSet ;
5 import java.util.Iterator ;
6 import java.util.List ;
7 import java.util.Map ;
8 import java.util.Set ;
9
10 import org.dom4j.Element;
11 import org.jbpm.graph.action.Script;
12 import org.jbpm.graph.def.Node;
13 import org.jbpm.graph.def.Transition;
14 import org.jbpm.graph.exe.ExecutionContext;
15 import org.jbpm.instantiation.Delegation;
16 import org.jbpm.jpdl.xml.JpdlXmlReader;
17 import org.jbpm.jpdl.xml.Parsable;
18
19
22 public class Decision extends Node implements Parsable {
23
24 private static final String DECISION_CONDITION_RESULT = "decision_condition_result";
25 private static final long serialVersionUID = 1L;
26
27 List decisionConditions = null;
28 Delegation decisionDelegation = null;
29
30 public Decision() {
31 }
32
33 public Decision(String name) {
34 super(name);
35 }
36
37 public void read(Element decisionElement, JpdlXmlReader jpdlReader) {
38 Element decisionHandlerElement = decisionElement.element("handler");
39 if (decisionHandlerElement!=null) {
40 decisionDelegation = new Delegation();
41 decisionDelegation.read(decisionHandlerElement, jpdlReader);
42
43 } else {
44 Iterator iter = decisionElement.elementIterator("transition");
45 while (iter.hasNext()) {
46 Element transitionElement = (Element) iter.next();
47 String transitionName = transitionElement.attributeValue("name");
48 String conditionExpression = transitionElement.elementText("condition");
49 if (decisionConditions==null) {
50 decisionConditions = new ArrayList ();
51 }
52 decisionConditions.add(new DecisionCondition(transitionName, conditionExpression));
53 }
54 }
55 }
56
57 public void execute(ExecutionContext executionContext) {
58 String transitionName = null;
59
60 try {
61 if (decisionDelegation!=null) {
62 DecisionHandler decisionHandler = (DecisionHandler) decisionDelegation.instantiate();
63 transitionName = decisionHandler.decide(executionContext);
64
65 } else {
66 Iterator iter = decisionConditions.iterator();
67 while ((iter.hasNext())
68 && (transitionName==null)) {
69 DecisionCondition decisionCondition = (DecisionCondition) iter.next();
70 if (decisionCondition.expression!=null) {
71 Script decisionConditionScript = new Script();
72 decisionConditionScript.setExpression("decision_condition_result = ("+decisionCondition.expression+");");
73 Map inputMap = decisionConditionScript.createInputMap(executionContext);
74 Set outputNames = new HashSet ();
75 outputNames.add(DECISION_CONDITION_RESULT);
76 Map outputMap = decisionConditionScript.eval(inputMap, outputNames);
77 Boolean result = (Boolean ) outputMap.get(DECISION_CONDITION_RESULT);
78 if (result.booleanValue()) {
79 transitionName = decisionCondition.transitionName;
80 }
81 } else {
82 transitionName = decisionCondition.transitionName;
83 }
84 }
85 }
86 } catch (Throwable exception) {
87 raiseException(exception, executionContext);
88 }
89
90 Transition transition = getLeavingTransition(transitionName);
91 if (transition==null) {
92 throw new RuntimeException ("decision '"+name+"' selected non existing transition '"+transitionName+"'" );
93 }
94 executionContext.leaveNode(transition);
95 }
96 }
97 |
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