001/* MBeanServerDelegate.java -- The management server delegate. 002 Copyright (C) 2006 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package javax.management; 039 040import gnu.javax.management.ListenerData; 041import gnu.classpath.SystemProperties; 042 043import java.net.InetAddress; 044import java.net.UnknownHostException; 045 046import java.util.ArrayList; 047import java.util.Date; 048import java.util.Iterator; 049import java.util.List; 050 051/** 052 * Provides an implementation of a delegate bean, which is associated 053 * with a management server. The delegate bean is responsible 054 * for providing metadata about the server and handling the 055 * registration and deregistration notifications. 056 * 057 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 058 * @since 1.5 059 */ 060public class MBeanServerDelegate 061 implements MBeanServerDelegateMBean, NotificationEmitter 062{ 063 064 /** 065 * The identifier of the server associated with this delegate. 066 */ 067 private String id; 068 069 /** 070 * The listeners registered with the delegate. 071 */ 072 private final List<ListenerData> listeners = 073 new ArrayList<ListenerData>(); 074 075 /** 076 * The sequence identifier used by the delegate. 077 */ 078 private long seqNo; 079 080 /** 081 * Default constructor which generates the id. 082 */ 083 public MBeanServerDelegate() 084 { 085 String hostName; 086 try 087 { 088 hostName = InetAddress.getLocalHost().getHostName(); 089 } 090 catch (UnknownHostException e) 091 { 092 hostName = "Unknown host"; 093 } 094 id = hostName + "_" + new Date().getTime(); 095 } 096 097 /** 098 * Registers the specified listener as a new recipient of 099 * notifications from the delegate. If non-null, the filter 100 * argument will be used to select which notifications are 101 * delivered. The supplied object will also be passed to 102 * the recipient with each notification. This should not 103 * be modified by the broadcaster, but instead should be 104 * passed unmodified to the listener. 105 * 106 * @param listener the new listener, who will receive 107 * notifications from this broadcasting bean. 108 * @param filter a filter to determine which notifications are 109 * delivered to the listener, or <code>null</code> 110 * if no filtering is required. 111 * @param passback an object to be passed to the listener with 112 * each notification. 113 * @throws IllegalArgumentException if <code>listener</code> is 114 * <code>null</code>. 115 * @see #removeNotificationListener(NotificationListener) 116 */ 117 public void addNotificationListener(NotificationListener listener, 118 NotificationFilter filter, 119 Object passback) 120 throws IllegalArgumentException 121 { 122 if (listener == null) 123 throw new IllegalArgumentException("A null listener was supplied."); 124 listeners.add(new ListenerData(listener, filter, passback)); 125 } 126 127 /** 128 * Returns the name of this Java Management eXtensions (JMX) implementation. 129 * 130 * @return the implementation name. 131 */ 132 public String getImplementationName() 133 { 134 return "GNU JMX"; 135 } 136 137 /** 138 * Returns the vendor of this Java Management eXtensions (JMX) implementation. 139 * 140 * @return the implementation vendor. 141 */ 142 public String getImplementationVendor() 143 { 144 return "The GNU Classpath Project"; 145 } 146 147 /** 148 * Returns the version of this Java Management eXtensions (JMX) implementation. 149 * 150 * @return the implementation version. 151 */ 152 public String getImplementationVersion() 153 { 154 return SystemProperties.getProperty("gnu.classpath.version"); 155 } 156 157 /** 158 * Returns the unique identifier for this management server. 159 * 160 * @return the unique id of the server. 161 */ 162 public String getMBeanServerId() 163 { 164 return id; 165 } 166 167 /** 168 * Returns an array describing the notifications this 169 * bean may send to its registered listeners. Ideally, this 170 * array should be complete, but in some cases, this may 171 * not be possible. However, be aware that some listeners 172 * may expect this to be so. 173 * 174 * @return the array of possible notifications. 175 */ 176 public MBeanNotificationInfo[] getNotificationInfo() 177 { 178 return new MBeanNotificationInfo[] 179 { 180 new MBeanNotificationInfo(new String[] 181 { 182 MBeanServerNotification.REGISTRATION_NOTIFICATION, 183 MBeanServerNotification.UNREGISTRATION_NOTIFICATION, 184 }, 185 MBeanServerNotification.class.getName(), 186 "Server registration notifications") 187 }; 188 } 189 190 /** 191 * Returns the name of this Java Management eXtensions (JMX) specification. 192 * 193 * @return the specification name. 194 */ 195 public String getSpecificationName() 196 { 197 return "JMX"; 198 } 199 200 201 /** 202 * Returns the vendor of this Java Management eXtensions (JMX) specification. 203 * 204 * @return the specification vendor. 205 */ 206 public String getSpecificationVendor() 207 { 208 return "Sun Microsystems"; 209 } 210 211 /** 212 * Returns the version of this Java Management eXtensions (JMX) specification. 213 * 214 * @return the specification version. 215 */ 216 public String getSpecificationVersion() 217 { 218 return "1.2"; 219 } 220 221 /** 222 * Removes the specified listener from the list of recipients 223 * of notifications from this bean. This includes all combinations 224 * of filters and passback objects registered for this listener. 225 * For more specific removal of listeners, see 226 * {@link #removeNotificationListener(NotificationListener, 227 * NotificationFilter, java.lang.Object)} 228 * 229 * @param listener the listener to remove. 230 * @throws ListenerNotFoundException if the specified listener 231 * is not registered with this bean. 232 * @see #addNotificationListener(NotificationListener, NotificationFilter, 233 * java.lang.Object) 234 */ 235 public void removeNotificationListener(NotificationListener listener) 236 throws ListenerNotFoundException 237 { 238 Iterator<ListenerData> it = listeners.iterator(); 239 boolean foundOne = false; 240 while (it.hasNext()) 241 { 242 if (it.next().getListener() == listener) 243 { 244 it.remove(); 245 foundOne = true; 246 } 247 } 248 if (!foundOne) 249 throw new ListenerNotFoundException("The specified listener, " + listener + 250 "is not registered with this bean."); 251 } 252 253 /** 254 * Removes the specified listener from the list of recipients 255 * of notifications from this delegate. Only the first instance with 256 * the supplied filter and passback object is removed. 257 * <code>null</code> is used as a valid value for these parameters, 258 * rather than as a way to remove all registration instances for 259 * the specified listener; for this behaviour instead, see 260 * {@link #removeNotificationListener(NotificationListener)}. 261 * 262 * @param listener the listener to remove. 263 * @param filter the filter of the listener to remove. 264 * @param passback the passback object of the listener to remove. 265 * @throws ListenerNotFoundException if the specified listener 266 * is not registered with this bean. 267 * @see #addNotificationListener(NotificationListener, NotificationFilter, 268 * java.lang.Object) 269 * @see #removeNotificationListener(NotificationListener) 270 */ 271 public void removeNotificationListener(NotificationListener listener, 272 NotificationFilter filter, 273 Object passback) 274 throws ListenerNotFoundException 275 { 276 if (!(listeners.remove(new ListenerData(listener, filter, passback)))) 277 { 278 throw new ListenerNotFoundException("The specified listener, " + listener + 279 " with filter " + filter + 280 "and passback " + passback + 281 ", is not registered with this bean."); 282 } 283 } 284 285 /** 286 * Allows the server to use the delegate to send a notification. 287 * If the supplied notification has a sequence number <= 0, then 288 * it is replaced with the delegate's own sequence number. 289 * 290 * @param notification the notification to send. 291 */ 292 public void sendNotification(Notification notification) 293 { 294 if (notification.getSequenceNumber() <= 0) 295 notification.setSequenceNumber(++seqNo); 296 for (ListenerData ldata : listeners) 297 { 298 NotificationFilter filter = ldata.getFilter(); 299 if (filter == null || filter.isNotificationEnabled(notification)) 300 ldata.getListener().handleNotification(notification, ldata.getPassback()); 301 } 302 } 303 304}