org.camunda.bpm.engine.impl.bpmn.behavior.ExclusiveGatewayActivityBehavior Maven / Gradle / Ivy
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* Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH
* under one or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information regarding copyright
* ownership. Camunda licenses this file to you under the Apache License,
* Version 2.0; you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.camunda.bpm.engine.impl.bpmn.behavior;
import java.util.Iterator;
import org.camunda.bpm.engine.impl.Condition;
import org.camunda.bpm.engine.impl.ProcessEngineLogger;
import org.camunda.bpm.engine.impl.bpmn.parser.BpmnParse;
import org.camunda.bpm.engine.impl.pvm.PvmTransition;
import org.camunda.bpm.engine.impl.pvm.delegate.ActivityExecution;
/**
* implementation of the Exclusive Gateway/XOR gateway/exclusive data-based gateway
* as defined in the BPMN specification.
*
* @author Joram Barrez
*/
public class ExclusiveGatewayActivityBehavior extends GatewayActivityBehavior {
protected static BpmnBehaviorLogger LOG = ProcessEngineLogger.BPMN_BEHAVIOR_LOGGER;
/**
* The default behaviour of BPMN, taking every outgoing sequence flow
* (where the condition evaluates to true), is not valid for an exclusive
* gateway.
*
* Hence, this behaviour is overriden and replaced by the correct behavior:
* selecting the first sequence flow which condition evaluates to true
* (or which hasn't got a condition) and leaving the activity through that
* sequence flow.
*
* If no sequence flow is selected (ie all conditions evaluate to false),
* then the default sequence flow is taken (if defined).
*/
@Override
public void doLeave(ActivityExecution execution) {
LOG.leavingActivity(execution.getActivity().getId());
PvmTransition outgoingSeqFlow = null;
String defaultSequenceFlow = (String) execution.getActivity().getProperty("default");
Iterator transitionIterator = execution.getActivity().getOutgoingTransitions().iterator();
while (outgoingSeqFlow == null && transitionIterator.hasNext()) {
PvmTransition seqFlow = transitionIterator.next();
Condition condition = (Condition) seqFlow.getProperty(BpmnParse.PROPERTYNAME_CONDITION);
if ( (condition == null && (defaultSequenceFlow == null || !defaultSequenceFlow.equals(seqFlow.getId())) )
|| (condition != null && condition.evaluate(execution)) ) {
LOG.outgoingSequenceFlowSelected(seqFlow.getId());
outgoingSeqFlow = seqFlow;
}
}
if (outgoingSeqFlow != null) {
execution.leaveActivityViaTransition(outgoingSeqFlow);
} else {
if (defaultSequenceFlow != null) {
PvmTransition defaultTransition = execution.getActivity().findOutgoingTransition(defaultSequenceFlow);
if (defaultTransition != null) {
execution.leaveActivityViaTransition(defaultTransition);
} else {
throw LOG.missingDefaultFlowException(execution.getActivity().getId(), defaultSequenceFlow);
}
} else {
//No sequence flow could be found, not even a default one
throw LOG.stuckExecutionException(execution.getActivity().getId());
}
}
}
}