org.mycore.common.events.MCREventHandler Maven / Gradle / Ivy
/*
* This file is part of *** M y C o R e ***
* See http://www.mycore.de/ for details.
*
* MyCoRe is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* MyCoRe is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with MyCoRe. If not, see .
*/
package org.mycore.common.events;
import org.mycore.common.MCRException;
/**
* Objects that implement this interface can react when some kind of predefined
* event happens in MyCoRe. Implementing classes are registered using the
* configuration property
*
* MCR.EventHandler.[objType].X.Class=[package and class name]
*
* where [objType] is the object type like "MCRObject" or "MCRFile" and X is a
* number starting from 1. For event handlers that are indexers of the searcher
* package, there is a special syntax
*
* MCR.EventHandler.[objType].X.Indexer=[searcherID]
*
* where [searcherID] is the ID of the searcher that also is an indexer. Event
* handlers are called in the same order as they are registered in the
* properties file.
*
* @author Frank Lützenkirchen
*/
public interface MCREventHandler {
/**
* Handles an event. The handler is responsible for filtering the event type
* it is interested in and wants to react on.
*
* @param evt
* the Event object containing information about the event
*/
void doHandleEvent(MCREvent evt) throws MCRException;
/**
* Handles rollback of event handling. The handler should roll back the
* changes that previously were made for this event, because a successor in
* the event handler list caused an exception.
*
* @param evt
* the Event object containing information about the event
*/
void undoHandleEvent(MCREvent evt) throws MCRException;
}