bpmn/mso-infrastructure-bpmn/src/main/java/org/onap/so/bpmn/core/plugins/WorkflowExceptionPlugin.java

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  * ONAP - SO
   4  * ================================================================================
   5  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Modifications Copyright (c) 2019 Samsung
   8  * ================================================================================
   9  * Licensed under the Apache License, Version 2.0 (the "License");
  10  * you may not use this file except in compliance with the License.
  11  * You may obtain a copy of the License at
  12  *
  13  *      http://www.apache.org/licenses/LICENSE-2.0
  14  *
  15  * Unless required by applicable law or agreed to in writing, software
  16  * distributed under the License is distributed on an "AS IS" BASIS,
  17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18  * See the License for the specific language governing permissions and
  19  * limitations under the License.
  20  * ============LICENSE_END=========================================================
  21  */
  22
  23 package org.onap.so.bpmn.core.plugins;
  24
  25 import java.util.ArrayList;
  26 import java.util.List;
  27 import java.util.concurrent.atomic.AtomicInteger;
  28 import org.camunda.bpm.engine.delegate.BpmnError;
  29 import org.camunda.bpm.engine.delegate.DelegateExecution;
  30 import org.camunda.bpm.engine.delegate.ExecutionListener;
  31 import org.camunda.bpm.engine.delegate.JavaDelegate;
  32 import org.camunda.bpm.engine.impl.bpmn.behavior.ClassDelegateActivityBehavior;
  33 import org.camunda.bpm.engine.impl.bpmn.parser.AbstractBpmnParseListener;
  34 import org.camunda.bpm.engine.impl.bpmn.parser.BpmnParseListener;
  35 import org.camunda.bpm.engine.impl.bpmn.parser.FieldDeclaration;
  36 import org.camunda.bpm.engine.impl.cfg.AbstractProcessEnginePlugin;
  37 import org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl;
  38 import org.camunda.bpm.engine.impl.persistence.entity.ProcessDefinitionEntity;
  39 import org.camunda.bpm.engine.impl.pvm.PvmTransition;
  40 import org.camunda.bpm.engine.impl.pvm.process.ActivityImpl;
  41 import org.camunda.bpm.engine.impl.pvm.process.TransitionImpl;
  42 import org.camunda.bpm.engine.impl.util.xml.Element;
  43 import org.onap.so.bpmn.core.WorkflowException;
  44 import org.springframework.stereotype.Component;
  45 import org.slf4j.Logger;
  46 import org.slf4j.LoggerFactory;
  47
  48 /**
  49  * This plugin does the following:
  50  * <ol>
  51  * <li>Adds logic at the start of every Call Activity to remove any existing WorkflowException object from the execution
  52  * (saving a copy of it in a different variable).</li>
  53  * <li>Adds logic at the end of every Call Activity to generate a MSOWorkflowException event if there is a
  54  * WorkflowException object in the execution.</li>
  55  * </ol>
  56  */
  57 @Component
  58 public class WorkflowExceptionPlugin extends AbstractProcessEnginePlugin {
  59     private static final Logger logger = LoggerFactory.getLogger(WorkflowExceptionPlugin.class);
  60
  61     @Override
  62     public void preInit(ProcessEngineConfigurationImpl processEngineConfiguration) {
  63         List<BpmnParseListener> preParseListeners = processEngineConfiguration.getCustomPreBPMNParseListeners();
  64
  65         if (preParseListeners == null) {
  66             preParseListeners = new ArrayList<>();
  67             processEngineConfiguration.setCustomPreBPMNParseListeners(preParseListeners);
  68         }
  69
  70         preParseListeners.add(new WorkflowExceptionParseListener());
  71     }
  72
  73     public static class WorkflowExceptionParseListener extends AbstractBpmnParseListener {
  74         @Override
  75         public void parseProcess(Element processElement, ProcessDefinitionEntity processDefinition) {
  76             AtomicInteger triggerTaskIndex = new AtomicInteger(1);
  77             List<ActivityImpl> activities = new ArrayList<>(processDefinition.getActivities());
  78             recurse(activities, triggerTaskIndex);
  79         }
  80
  81         /**
  82          * Helper method that recurses (into subprocesses) over all the listed activities.
  83          *
  84          * @param activities a list of workflow activities
  85          * @param triggerTaskIndex the index of the next trigger task (mutable)
  86          */
  87         private void recurse(List<ActivityImpl> activities, AtomicInteger triggerTaskIndex) {
  88             for (ActivityImpl activity : activities) {
  89                 String type = (String) activity.getProperty("type");
  90
  91                 if ("callActivity".equals(type)) {
  92                     // Add a WorkflowExceptionResetListener to clear the WorkflowException
  93                     // variable when each Call Activity starts.
  94
  95                     activity.addListener(ExecutionListener.EVENTNAME_START, new WorkflowExceptionResetListener());
  96
  97                     // Add a WorkflowExceptionTriggerTask after the call activity.
  98                     // It must be a task because a listener cannot be used to generate
  99                     // an event. Throwing BpmnError from an execution listener will
 100                     // cause the process to die.
 101
 102                     List<PvmTransition> outTransitions = new ArrayList<>(activity.getOutgoingTransitions());
 103
 104                     for (PvmTransition transition : outTransitions) {
 105                         String triggerTaskId = "WorkflowExceptionTriggerTask_" + triggerTaskIndex;
 106
 107                         ActivityImpl triggerTask = activity.getFlowScope().createActivity(triggerTaskId);
 108
 109                         ClassDelegateActivityBehavior behavior = new ClassDelegateActivityBehavior(
 110                                 WorkflowExceptionTriggerTask.class.getName(), new ArrayList<>(0));
 111
 112                         triggerTask.setActivityBehavior(behavior);
 113                         triggerTask.setName("Workflow Exception Trigger Task " + triggerTaskIndex);
 114                         triggerTaskIndex.getAndIncrement();
 115
 116                         TransitionImpl transitionImpl = (TransitionImpl) transition;
 117                         TransitionImpl triggerTaskOutTransition = triggerTask.createOutgoingTransition();
 118                         triggerTaskOutTransition.setDestination((ActivityImpl) transitionImpl.getDestination());
 119                         transitionImpl.setDestination(triggerTask);
 120                     }
 121                 } else if ("subProcess".equals(type)) {
 122                     recurse(new ArrayList<>(activity.getActivities()), triggerTaskIndex);
 123                 }
 124             }
 125         }
 126     }
 127
 128     /**
 129      * If there is a WorkflowException object in the execution, this method removes it (saving a copy of it in a
 130      * different variable).
 131      */
 132     public static class WorkflowExceptionResetListener implements ExecutionListener {
 133         public void notify(DelegateExecution execution) throws Exception {
 134             Object workflowException = execution.getVariable("WorkflowException");
 135
 136             if (workflowException instanceof WorkflowException) {
 137                 int index = 1;
 138                 String saveName = "SavedWorkflowException" + index;
 139                 while (execution.getVariable(saveName) != null) {
 140                     saveName = "SavedWorkflowException" + (++index);
 141                 }
 142
 143                 logger.debug("WorkflowExceptionResetTask is moving WorkflowException to " + saveName);
 144
 145                 execution.setVariable(saveName, workflowException);
 146                 execution.setVariable("WorkflowException", null);
 147             }
 148         }
 149     }
 150
 151     /**
 152      * Generates an MSOWorkflowException event if there is a WorkflowException object in the execution.
 153      */
 154     public static class WorkflowExceptionTriggerTask implements JavaDelegate {
 155         public void execute(DelegateExecution execution) throws Exception {
 156             if (execution.getVariable("WorkflowException") instanceof WorkflowException) {
 157                 logger.debug("WorkflowExceptionTriggerTask is generating a MSOWorkflowException event");
 158                 throw new BpmnError("MSOWorkflowException");
 159             }
 160         }
 161     }
 162 }