001 /* MBeanServerDelegate.java -- The management server delegate. 002 Copyright (C) 2006 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 package javax.management; 039 040 import gnu.javax.management.ListenerData; 041 import gnu.classpath.SystemProperties; 042 043 import java.net.InetAddress; 044 import java.net.UnknownHostException; 045 046 import java.util.ArrayList; 047 import java.util.Date; 048 import java.util.Iterator; 049 import 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 */ 060 public 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 listeners = new ArrayList(); 073 074 /** 075 * The sequence identifier used by the delegate. 076 */ 077 private long seqNo; 078 079 /** 080 * Default constructor which generates the id. 081 */ 082 public MBeanServerDelegate() 083 { 084 String hostName; 085 try 086 { 087 hostName = InetAddress.getLocalHost().getHostName(); 088 } 089 catch (UnknownHostException e) 090 { 091 hostName = "Unknown host"; 092 } 093 id = hostName + "_" + new Date().getTime(); 094 } 095 096 /** 097 * Registers the specified listener as a new recipient of 098 * notifications from the delegate. If non-null, the filter 099 * argument will be used to select which notifications are 100 * delivered. The supplied object will also be passed to 101 * the recipient with each notification. This should not 102 * be modified by the broadcaster, but instead should be 103 * passed unmodified to the listener. 104 * 105 * @param listener the new listener, who will receive 106 * notifications from this broadcasting bean. 107 * @param filter a filter to determine which notifications are 108 * delivered to the listener, or <code>null</code> 109 * if no filtering is required. 110 * @param passback an object to be passed to the listener with 111 * each notification. 112 * @throws IllegalArgumentException if <code>listener</code> is 113 * <code>null</code>. 114 * @see #removeNotificationListener(NotificationListener) 115 */ 116 public void addNotificationListener(NotificationListener listener, 117 NotificationFilter filter, 118 Object passback) 119 throws IllegalArgumentException 120 { 121 if (listener == null) 122 throw new IllegalArgumentException("A null listener was supplied."); 123 listeners.add(new ListenerData(listener, filter, passback)); 124 } 125 126 /** 127 * Returns the name of this Java Management eXtensions (JMX) implementation. 128 * 129 * @return the implementation name. 130 */ 131 public String getImplementationName() 132 { 133 return "GNU JMX"; 134 } 135 136 /** 137 * Returns the vendor of this Java Management eXtensions (JMX) implementation. 138 * 139 * @return the implementation vendor. 140 */ 141 public String getImplementationVendor() 142 { 143 return "The GNU Classpath Project"; 144 } 145 146 /** 147 * Returns the version of this Java Management eXtensions (JMX) implementation. 148 * 149 * @return the implementation version. 150 */ 151 public String getImplementationVersion() 152 { 153 return SystemProperties.getProperty("gnu.classpath.version"); 154 } 155 156 /** 157 * Returns the unique identifier for this management server. 158 * 159 * @return the unique id of the server. 160 */ 161 public String getMBeanServerId() 162 { 163 return id; 164 } 165 166 /** 167 * Returns an array describing the notifications this 168 * bean may send to its registered listeners. Ideally, this 169 * array should be complete, but in some cases, this may 170 * not be possible. However, be aware that some listeners 171 * may expect this to be so. 172 * 173 * @return the array of possible notifications. 174 */ 175 public MBeanNotificationInfo[] getNotificationInfo() 176 { 177 return new MBeanNotificationInfo[] 178 { 179 new MBeanNotificationInfo(new String[] 180 { 181 MBeanServerNotification.REGISTRATION_NOTIFICATION, 182 MBeanServerNotification.UNREGISTRATION_NOTIFICATION, 183 }, 184 MBeanServerNotification.class.getName(), 185 "Server registration notifications") 186 }; 187 } 188 189 /** 190 * Returns the name of this Java Management eXtensions (JMX) specification. 191 * 192 * @return the specification name. 193 */ 194 public String getSpecificationName() 195 { 196 return "JMX"; 197 } 198 199 200 /** 201 * Returns the vendor of this Java Management eXtensions (JMX) specification. 202 * 203 * @return the specification vendor. 204 */ 205 public String getSpecificationVendor() 206 { 207 return "Sun Microsystems"; 208 } 209 210 /** 211 * Returns the version of this Java Management eXtensions (JMX) specification. 212 * 213 * @return the specification version. 214 */ 215 public String getSpecificationVersion() 216 { 217 return "1.2"; 218 } 219 220 /** 221 * Removes the specified listener from the list of recipients 222 * of notifications from this bean. This includes all combinations 223 * of filters and passback objects registered for this listener. 224 * For more specific removal of listeners, see 225 * {@link #removeNotificationListener(NotificationListener, 226 * NotificationFilter, java.lang.Object)} 227 * 228 * @param listener the listener to remove. 229 * @throws ListenerNotFoundException if the specified listener 230 * is not registered with this bean. 231 * @see #addNotificationListener(NotificationListener, NotificationFilter, 232 * java.lang.Object) 233 */ 234 public void removeNotificationListener(NotificationListener listener) 235 throws ListenerNotFoundException 236 { 237 Iterator it = listeners.iterator(); 238 boolean foundOne = false; 239 while (it.hasNext()) 240 { 241 ListenerData data = (ListenerData) it.next(); 242 if (data.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 Iterator it = listeners.iterator(); 297 while (it.hasNext()) 298 { 299 ListenerData ldata = (ListenerData) it.next(); 300 NotificationFilter filter = ldata.getFilter(); 301 if (filter == null || filter.isNotificationEnabled(notification)) 302 ldata.getListener().handleNotification(notification, ldata.getPassback()); 303 } 304 } 305 306 }