/* Licensed under the Apache License, Version 2.0 (the "License");
* 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.application.impl.event;
import java.util.concurrent.Callable;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.camunda.bpm.application.ProcessApplicationInterface;
import org.camunda.bpm.application.ProcessApplicationReference;
import org.camunda.bpm.application.ProcessApplicationUnavailableException;
import org.camunda.bpm.engine.ProcessEngineException;
import org.camunda.bpm.engine.delegate.DelegateExecution;
import org.camunda.bpm.engine.delegate.DelegateTask;
import org.camunda.bpm.engine.delegate.ExecutionListener;
import org.camunda.bpm.engine.delegate.TaskListener;
import org.camunda.bpm.engine.impl.context.Context;
import org.camunda.bpm.engine.impl.context.ProcessApplicationContextUtil;
import org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity;
/**
* <p>{@link ExecutionListener} and {@link TaskListener} implementation delegating to
* the {@link ExecutionListener} and {@link TaskListener} provided by a
* {@link ProcessApplicationInterface ProcessApplication}.</p>
*
* <p>If the process application does not provide an execution listener (ie.
* {@link ProcessApplicationInterface#getExecutionListener()} returns null), the
* request is silently ignored.</p>
*
* <p>If the process application does not provide a task listener (ie.
* {@link ProcessApplicationInterface#getTaskListener()} returns null), the
* request is silently ignored.</p>
*
*
* @author Daniel Meyer
* @see ProcessApplicationInterface#getExecutionListener()
* @see ProcessApplicationInterface#getTaskListener()
*
*/
public class ProcessApplicationEventListenerDelegate implements ExecutionListener, TaskListener {
private Logger LOG = Logger.getLogger(ProcessApplicationEventListenerDelegate.class.getName());
public void notify(final DelegateExecution execution) throws Exception {
Callable<Void> notification = new Callable<Void>() {
public Void call() throws Exception {
notifyExecutionListener(execution);
return null;
}
};
performNotification(execution, notification);
}
public void notify(final DelegateTask delegateTask){
if(delegateTask.getExecution() == null) {
LOG.log(Level.FINE, "Task {0} not related to an execution, target process application cannot be determined.", new Object[] { delegateTask });
} else {
final DelegateExecution execution = delegateTask.getExecution();
Callable<Void> notification = new Callable<Void>() {
public Void call() throws Exception {
notifyTaskListener(delegateTask);
return null;
}
};
try {
performNotification(execution, notification);
} catch(Exception e) {
throw new ProcessEngineException("Exception while notifying process application task listener.", e);
}
}
}
protected void performNotification(final DelegateExecution execution, Callable<Void> notification) throws Exception {
final ProcessApplicationReference processApp = ProcessApplicationContextUtil.getTargetProcessApplication((ExecutionEntity) execution);
if (processApp == null) {
// ignore silently
LOG.log(Level.FINE, "No target process application found for execution {0}", new Object[] { execution });
} else {
if (ProcessApplicationContextUtil.requiresContextSwitch(processApp)) {
// this should not be necessary since context switch is already performed by OperationContext and / or DelegateInterceptor
Context.executeWithinProcessApplication(notification, processApp);
} else {
// context switch already performed
notification.call();
}
}
}
protected void notifyExecutionListener(DelegateExecution execution) throws Exception {
ProcessApplicationReference processApp = Context.getCurrentProcessApplication();
try {
ProcessApplicationInterface processApplication = processApp.getProcessApplication();
ExecutionListener executionListener = processApplication.getExecutionListener();
if(executionListener != null) {
executionListener.notify(execution);
} else {
LOG.log(Level.FINE, "Target process application '"+processApp.getName()+"' does not provide an ExecutionListener.");
}
} catch (ProcessApplicationUnavailableException e) {
// Process Application unavailable => ignore silently
LOG.log(Level.FINE, "Target process application '"+processApp.getName()+"' unavailable", e);
}
}
protected void notifyTaskListener(DelegateTask task) throws Exception {
ProcessApplicationReference processApp = Context.getCurrentProcessApplication();
try {
ProcessApplicationInterface processApplication = processApp.getProcessApplication();
TaskListener taskListener = processApplication.getTaskListener();
if(taskListener != null) {
taskListener.notify(task);
} else {
LOG.log(Level.FINE, "Target process application '"+processApp.getName()+"' does not provide a TaskListener.");
}
} catch (ProcessApplicationUnavailableException e) {
// Process Application unavailable => ignore silently
LOG.log(Level.FINE, "Target process application '"+processApp.getName()+"' unavailable", e);
}
}
}