Flowable-6.7.2 源码注释地址：https://github.com/solojin/flowable-6.7.2-annotated

BoundaryEventRegistryEventActivityBehavior 边界事件注册事件活动行为类

/**
 * 边界事件注册事件活动行为类
 * 
 * @author Tijs Rademakers
 */
public class BoundaryEventRegistryEventActivityBehavior extends BoundaryEventActivityBehavior {

    private static final long serialVersionUID = 1L;

    protected String eventDefinitionKey;

    public BoundaryEventRegistryEventActivityBehavior(String eventDefinitionKey, boolean interrupting) {
        super(interrupting);
        this.eventDefinitionKey = eventDefinitionKey;
    }

    @Override
    public void execute(DelegateExecution execution) {
        CommandContext commandContext = Context.getCommandContext();
        ExecutionEntity executionEntity = (ExecutionEntity) execution;

        ProcessEngineConfigurationImpl processEngineConfiguration = CommandContextUtil.getProcessEngineConfiguration(commandContext);
        String eventDefinitionKey = getEventDefinitionKey(executionEntity, processEngineConfiguration);
        EventSubscriptionEntity eventSubscription = (EventSubscriptionEntity) processEngineConfiguration.getEventSubscriptionServiceConfiguration()
                .getEventSubscriptionService().createEventSubscriptionBuilder()
                        .eventType(eventDefinitionKey)
                        .executionId(executionEntity.getId())
                        .processInstanceId(executionEntity.getProcessInstanceId())
                        .activityId(executionEntity.getCurrentActivityId())
                        .processDefinitionId(executionEntity.getProcessDefinitionId())
                        .scopeType(ScopeTypes.BPMN)
                        .tenantId(executionEntity.getTenantId())
                        .configuration(CorrelationUtil.getCorrelationKey(BpmnXMLConstants.ELEMENT_EVENT_CORRELATION_PARAMETER, commandContext, executionEntity))
                        .create();
        
        CountingEntityUtil.handleInsertEventSubscriptionEntityCount(eventSubscription);
        executionEntity.getEventSubscriptions().add(eventSubscription);
    }

    @Override
    public void trigger(DelegateExecution execution, String triggerName, Object triggerData) {
        ExecutionEntity executionEntity = (ExecutionEntity) execution;
        BoundaryEvent boundaryEvent = (BoundaryEvent) execution.getCurrentFlowElement();
        
        Object eventInstance = execution.getTransientVariables().get(EventConstants.EVENT_INSTANCE);
        if (eventInstance instanceof EventInstance) {
            EventInstanceBpmnUtil.handleEventInstanceOutParameters(execution, boundaryEvent, (EventInstance) eventInstance);
        }

        if (boundaryEvent.isCancelActivity()) {
            ProcessEngineConfigurationImpl processEngineConfiguration = CommandContextUtil.getProcessEngineConfiguration();
            EventSubscriptionService eventSubscriptionService = processEngineConfiguration.getEventSubscriptionServiceConfiguration().getEventSubscriptionService();
            List<EventSubscriptionEntity> eventSubscriptions = executionEntity.getEventSubscriptions();
            
            String eventDefinitionKey = getEventDefinitionKey(executionEntity, processEngineConfiguration);
            for (EventSubscriptionEntity eventSubscription : eventSubscriptions) {
                if (Objects.equals(eventDefinitionKey, eventSubscription.getEventType())) {
                    eventSubscriptionService.deleteEventSubscription(eventSubscription);
                    CountingEntityUtil.handleDeleteEventSubscriptionEntityCount(eventSubscription);
                }
            }
        }

        super.trigger(executionEntity, triggerName, triggerData);
    }

    protected String getEventDefinitionKey(ExecutionEntity executionEntity, ProcessEngineConfigurationImpl processEngineConfiguration) {
        Object key = null;

        if (StringUtils.isNotEmpty(eventDefinitionKey)) {
            Expression expression = processEngineConfiguration.getExpressionManager()
                    .createExpression(eventDefinitionKey);
            key = expression.getValue(executionEntity);
        }

        if (key == null) {
            throw new FlowableException("Could not resolve key for: " + eventDefinitionKey);
        }

        return key.toString();
    }
}

CancelBoundaryEventActivityBehavior 取消边界事件活动行为类

/**
 * 取消边界事件活动行为类
 *
 * @author Daniel Meyer
 */
public class CancelBoundaryEventActivityBehavior extends FlowNodeActivityBehavior {

    @Override
    public void execute(DelegateExecution execution) {
        ActivityExecution activityExecution = (ActivityExecution) execution;
        List<CompensateEventSubscriptionEntity> eventSubscriptions = ((ExecutionEntity) execution).getCompensateEventSubscriptions();

        if (eventSubscriptions.isEmpty()) {
            leave(activityExecution);
        } else {
            // 取消边界总是同步的
            ScopeUtil.throwCompensationEvent(eventSubscriptions, activityExecution, false);
        }
    }

    @Override
    public void signal(ActivityExecution execution, String signalName, Object signalData) throws Exception {
        // 加入补偿执行
        if (execution.getExecutions().isEmpty()) {
            leave(execution);
        } else {
            ((ExecutionEntity) execution).forceUpdate();
        }
    }

}

BoundaryConditionalEventActivityBehavior 边界条件事件活动行为类

/**
 * 边界条件事件活动行为类
 *
 * 条件边界事件（Conditional Boundary Event）类似如监听器，如果满足一个特定的条件，它就会被触发。
 *
 * @author Tijs Rademakers
 */
public class BoundaryConditionalEventActivityBehavior extends BoundaryEventActivityBehavior {

    private static final long serialVersionUID = 1L;

    protected ConditionalEventDefinition conditionalEventDefinition;
    protected String conditionExpression;

    public BoundaryConditionalEventActivityBehavior(ConditionalEventDefinition conditionalEventDefinition, String conditionExpression, boolean interrupting) {
        super(interrupting);
        this.conditionalEventDefinition = conditionalEventDefinition;
        this.conditionExpression = conditionExpression;
    }

    @Override
    public void execute(DelegateExecution execution) {
        ExecutionEntity executionEntity = (ExecutionEntity) execution;

        ProcessEngineConfigurationImpl processEngineConfiguration = CommandContextUtil.getProcessEngineConfiguration();
        FlowableEventDispatcher eventDispatcher = processEngineConfiguration.getEventDispatcher();
        if (eventDispatcher != null && eventDispatcher.isEnabled()) {
            eventDispatcher.dispatchEvent(FlowableEventBuilder.createConditionalEvent(FlowableEngineEventType.ACTIVITY_CONDITIONAL_WAITING, executionEntity.getActivityId(), 
                    conditionExpression, executionEntity.getId(), executionEntity.getProcessInstanceId(), executionEntity.getProcessDefinitionId()),
                    processEngineConfiguration.getEngineCfgKey());
        }
    }
    
    @Override
    public void trigger(DelegateExecution execution, String triggerName, Object triggerData) {
        CommandContext commandContext = Context.getCommandContext();
        ExecutionEntity executionEntity = (ExecutionEntity) execution;

        ProcessEngineConfigurationImpl processEngineConfiguration = CommandContextUtil.getProcessEngineConfiguration(commandContext);
        Expression expression = processEngineConfiguration.getExpressionManager().createExpression(conditionExpression);
        Object result = expression.getValue(execution);
        if (result instanceof Boolean && (Boolean) result) {
            processEngineConfiguration.getActivityInstanceEntityManager().recordActivityStart(executionEntity);
            
            FlowableEventDispatcher eventDispatcher = processEngineConfiguration.getEventDispatcher();
            if (eventDispatcher != null && eventDispatcher.isEnabled()) {
                eventDispatcher.dispatchEvent(FlowableEventBuilder.createConditionalEvent(FlowableEngineEventType.ACTIVITY_CONDITIONAL_RECEIVED, executionEntity.getActivityId(), 
                        conditionExpression, executionEntity.getId(), executionEntity.getProcessInstanceId(), executionEntity.getProcessDefinitionId()),
                        processEngineConfiguration.getEngineCfgKey());
            }
            
            if (interrupting) {
                executeInterruptingBehavior(executionEntity, commandContext);
            } else {
                executeNonInterruptingBehavior(executionEntity, commandContext);
            }
        }
    }
}

BoundaryVariableListenerEventActivityBehavior 边界变量监听器事件活动行为类

/**
 * 边界变量监听器事件活动行为类
 *
 * @author Joram Barrez
 * @author Tijs Rademakers
 */
public class BoundaryVariableListenerEventActivityBehavior extends BoundaryEventActivityBehavior {

    private static final long serialVersionUID = 1L;

    protected VariableListenerEventDefinition variableListenerEventDefinition;

    public BoundaryVariableListenerEventActivityBehavior(VariableListenerEventDefinition variableListenerEventDefinition, boolean interrupting) {
        super(interrupting);
        this.variableListenerEventDefinition = variableListenerEventDefinition;
    }

    @Override
    public void execute(DelegateExecution execution) {
        CommandContext commandContext = Context.getCommandContext();
        ExecutionEntity executionEntity = (ExecutionEntity) execution;

        ProcessEngineConfigurationImpl processEngineConfiguration = CommandContextUtil.getProcessEngineConfiguration(commandContext);
        
        String configuration = null;
        if (StringUtils.isNotEmpty(variableListenerEventDefinition.getVariableChangeType())) {
            ObjectNode configurationNode = processEngineConfiguration.getObjectMapper().createObjectNode();
            configurationNode.put(VariableListenerEventDefinition.CHANGE_TYPE_PROPERTY, variableListenerEventDefinition.getVariableChangeType());
            configuration = configurationNode.toString();
        }
        
        EventSubscriptionEntity eventSubscription = (EventSubscriptionEntity) processEngineConfiguration.getEventSubscriptionServiceConfiguration()
                .getEventSubscriptionService().createEventSubscriptionBuilder()
                    .eventType("variable")
                    .eventName(variableListenerEventDefinition.getVariableName())
                    .configuration(configuration)
                    .executionId(executionEntity.getId())
                    .processInstanceId(executionEntity.getProcessInstanceId())
                    .activityId(executionEntity.getCurrentActivityId())
                    .processDefinitionId(executionEntity.getProcessDefinitionId())
                    .tenantId(executionEntity.getTenantId())
                    .create();
        
        CountingEntityUtil.handleInsertEventSubscriptionEntityCount(eventSubscription);
        executionEntity.getEventSubscriptions().add(eventSubscription);
    }

    @Override
    public void trigger(DelegateExecution execution, String triggerName, Object triggerData) {
        ExecutionEntity executionEntity = (ExecutionEntity) execution;
        BoundaryEvent boundaryEvent = (BoundaryEvent) execution.getCurrentFlowElement();
        
        if (boundaryEvent.isCancelActivity()) {
            CommandContext commandContext = Context.getCommandContext();
            
            ProcessEngineConfigurationImpl processEngineConfiguration = CommandContextUtil.getProcessEngineConfiguration(commandContext);
            EventSubscriptionService eventSubscriptionService = processEngineConfiguration.getEventSubscriptionServiceConfiguration().getEventSubscriptionService();
            List<EventSubscriptionEntity> eventSubscriptions = executionEntity.getEventSubscriptions();
            for (EventSubscriptionEntity eventSubscription : eventSubscriptions) {
                if ("variable".equals(eventSubscription.getEventType()) && 
                        variableListenerEventDefinition.getVariableName().equals(eventSubscription.getEventName())) {
                    
                    eventSubscriptionService.deleteEventSubscription(eventSubscription);
                    CountingEntityUtil.handleDeleteEventSubscriptionEntityCount(eventSubscription);
                }
            }
        }

        super.trigger(executionEntity, triggerName, triggerData);
    }
}