001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.xbean.kernel.standard; 018 019 import java.util.ArrayList; 020 import java.util.Iterator; 021 import java.util.List; 022 023 import java.util.concurrent.CopyOnWriteArrayList; 024 import org.apache.xbean.kernel.KernelMonitor; 025 import org.apache.xbean.kernel.ServiceMonitor; 026 import org.apache.xbean.kernel.ServiceEvent; 027 import org.apache.xbean.kernel.KernelErrorsError; 028 029 /** 030 * The KernelMonitorBroadcaster broadcasts kernel events to registered kernel monitors. 031 * 032 * @author Dain Sundstrom 033 * @version $Id$ 034 * @since 2.0 035 */ 036 public class KernelMonitorBroadcaster implements KernelMonitor { 037 /** 038 * The monitors of kernel events. 039 */ 040 private final CopyOnWriteArrayList kernelMonitors = new CopyOnWriteArrayList(); 041 042 /** 043 * Adds a kernel monitor. 044 * 045 * @param kernelMonitor the kernel monitor to add 046 */ 047 public void addKernelMonitor(KernelMonitor kernelMonitor) { 048 kernelMonitors.addIfAbsent(kernelMonitor); 049 } 050 051 /** 052 * Removes a kernel monitor. 053 * 054 * @param kernelMonitor the kernel monitor to remove 055 */ 056 public void removeKernelMonitor(KernelMonitor kernelMonitor) { 057 kernelMonitors.remove(kernelMonitor); 058 } 059 060 /** 061 * {@inheritDoc} 062 */ 063 public void serviceNotificationError(ServiceMonitor serviceMonitor, ServiceEvent serviceEvent, Throwable throwable) { 064 List errors = new ArrayList(); 065 for (Iterator iterator = kernelMonitors.iterator(); iterator.hasNext();) { 066 KernelMonitor kernelMonitor = (KernelMonitor) iterator.next(); 067 try { 068 kernelMonitor.serviceNotificationError(serviceMonitor, serviceEvent, throwable); 069 } catch (RuntimeException ignored) { 070 // ignore - we did our best to notify the world 071 } catch (Error e) { 072 errors.add(e); 073 } 074 } 075 if (!errors.isEmpty()) { 076 throw new KernelErrorsError(errors); 077 } 078 } 079 }