001/* 002 * Copyright (c) 2006-2011 Nuxeo SA (http://nuxeo.com/) and others. 003 * 004 * All rights reserved. This program and the accompanying materials 005 * are made available under the terms of the Eclipse Public License v1.0 006 * which accompanies this distribution, and is available at 007 * http://www.eclipse.org/legal/epl-v10.html 008 * 009 * Contributors: 010 * Nuxeo - initial API and implementation 011 * 012 * $Id$ 013 */ 014 015package org.nuxeo.runtime.services.event; 016 017import java.util.Arrays; 018 019import org.apache.commons.logging.Log; 020import org.apache.commons.logging.LogFactory; 021import org.nuxeo.common.xmap.annotation.XNode; 022import org.nuxeo.common.xmap.annotation.XNodeList; 023import org.nuxeo.common.xmap.annotation.XObject; 024 025/** 026 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a> 027 */ 028@XObject("listener") 029public class ListenerDescriptor { 030 031 private static final NullListener NULL_LISTENER = new NullListener(); 032 033 private static final Log log = LogFactory.getLog(ListenerDescriptor.class); 034 035 @XNodeList(value = "topic", type = String[].class, componentType = String.class) 036 String[] topics; 037 038 EventListener listener; 039 040 @XNode("@class") 041 public void setListener(Class<EventListener> listenerClass) { 042 try { 043 listener = listenerClass.newInstance(); 044 } catch (ReflectiveOperationException e) { 045 log.error(e); 046 listener = NULL_LISTENER; 047 } 048 } 049 050 @Override 051 public String toString() { 052 return listener + " { " + Arrays.toString(topics) + " }"; 053 } 054 055} 056 057class NullListener implements EventListener { 058 059 @Override 060 public boolean aboutToHandleEvent(Event event) { 061 return false; 062 } 063 064 @Override 065 public void handleEvent(Event event) { 066 } 067 068}