org.camunda.bpm.engine.impl.history.event.HistoryEventProcessor Maven / Gradle / Ivy
/*
* 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.history.event;
import java.util.Collections;
import java.util.List;
import org.camunda.bpm.engine.ProcessEngineConfiguration;
import org.camunda.bpm.engine.impl.context.Context;
import org.camunda.bpm.engine.impl.history.handler.HistoryEventHandler;
import org.camunda.bpm.engine.impl.history.producer.HistoryEventProducer;
/**
* The {@link HistoryEventProcessor} should be used to process an history event.
*
* The {@link HistoryEvent} will be created with the help of the {@link HistoryEventProducer}
* from the {@link ProcessEngineConfiguration} and the given implementation of the
* {@link HistoryEventCreator} which uses the producer object to create an
* {@link HistoryEvent}. The {@link HistoryEvent} will be handled by the
* {@link HistoryEventHandler} from the {@link ProcessEngineConfiguration}.
*
* @author Christopher Zell
* @since 7.5
*/
public class HistoryEventProcessor {
/**
* The {@link HistoryEventCreator} interface which is used to interchange the implementation
* of the creation of different HistoryEvents.
*/
public static class HistoryEventCreator {
/**
* Creates the {@link HistoryEvent} with the help off the given
* {@link HistoryEventProducer}.
*
* @param producer the producer which is used for the creation
* @return the created {@link HistoryEvent}
*/
public HistoryEvent createHistoryEvent(HistoryEventProducer producer) {
return null;
}
public List createHistoryEvents(HistoryEventProducer producer) {
return Collections.emptyList();
}
public void postHandleSingleHistoryEventCreated(HistoryEvent event) {
return;
}
}
/**
* Process an {@link HistoryEvent} and handle them directly after creation.
* The {@link HistoryEvent} is created with the help of the given
* {@link HistoryEventCreator} implementation.
*
* @param creator the creator is used to create the {@link HistoryEvent} which should be thrown
*/
public static void processHistoryEvents(HistoryEventCreator creator) {
HistoryEventProducer historyEventProducer = Context.getProcessEngineConfiguration().getHistoryEventProducer();
HistoryEventHandler historyEventHandler = Context.getProcessEngineConfiguration().getHistoryEventHandler();
HistoryEvent singleEvent = creator.createHistoryEvent(historyEventProducer);
if (singleEvent != null) {
historyEventHandler.handleEvent(singleEvent);
creator.postHandleSingleHistoryEventCreated(singleEvent);
}
List eventList = creator.createHistoryEvents(historyEventProducer);
historyEventHandler.handleEvents(eventList);
}
}