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Diffstat (limited to 'libjava/classpath/javax/management/NotificationBroadcasterSupport.java')
| -rw-r--r-- | libjava/classpath/javax/management/NotificationBroadcasterSupport.java | 389 |
1 files changed, 0 insertions, 389 deletions
diff --git a/libjava/classpath/javax/management/NotificationBroadcasterSupport.java b/libjava/classpath/javax/management/NotificationBroadcasterSupport.java deleted file mode 100644 index 28b8148..0000000 --- a/libjava/classpath/javax/management/NotificationBroadcasterSupport.java +++ /dev/null @@ -1,389 +0,0 @@ -/* NotificationBroadcasterSupport.java -- Supporting implementation. - Copyright (C) 2007 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath 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 2, or (at your option) -any later version. - -GNU Classpath 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 GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - -package javax.management; - -import gnu.javax.management.ListenerData; - -import java.util.ArrayList; -import java.util.Iterator; -import java.util.List; - -import java.util.concurrent.Executor; - -/** - * <p> - * Provides an implementation of the {@link NotificationEmitter} - * interface, which beans may utilise by extension. By default, - * a synchronous dispatch system is provided, whereby the - * {@link #handleNotification(NotificationListener, Notification, - * Object)} is called once per listener by - * {*@link #sendNotification(Notification)} before returning. - * Thus, unless the listener is remote, it will have received - * the notification before the method returns. - * This may be changed by overriding the <code>handleNotification</code> - * method, or by providing an {@link java.util.concurrent.Executor} to - * use. With the latter, the dispatch of a notification to a particular - * listener will form one task performed by the executor. - * </p> - * <p> - * Any exceptions thrown by the dispatch process will be caught, allowing - * other listeners to still receive the notification. However, any - * {@link Error}s that are thrown will be propogated to the caller of - * {@link #sendNotification(Notification)}. - * </p> - * - * @author Andrew John Hughes (gnu_andrew@member.fsf.org) - * @since 1.5 - */ -public class NotificationBroadcasterSupport - implements NotificationEmitter -{ - - /** - * The executor for dispatch, or - * <code>null</code> if this thread should - * handle dispatch itself. - */ - private Executor executor; - - /** - * An array containing information on each - * notification, or <code>null</code> if an - * empty array should be returned by - * {@link #getNotificationInfo()}. - */ - private MBeanNotificationInfo[] info; - - /** - * The list of listeners registered with - * this broadcaster. - */ - private final List<ListenerData> listeners = - new ArrayList<ListenerData>(); - - /** - * Constructs a {@link NotificationBroadcasterSupport} using - * the default synchronous dispatch model, where a single - * thread sends the notification to all listeners. This - * is equivalent to calling - * <code>NotificationBroadcasterSupport(null, null)</code>. - */ - public NotificationBroadcasterSupport() - { - this(null, (MBeanNotificationInfo[]) null); - } - - /** - * Constructs a {@link NotificationBroadcasterSupport} where - * the specified (@link java.util.concurrent.Executor} is used - * to perform each invocation of the - * {@link #handleNotification(NotificationListener, Notification, - * Object)} method. Filtering is performed beforehand, by this - * thread; only calls which have successfully passed through the - * filter are sent to the executor. This is equivalent to calling - * <code>NotificationBroadcasterSupport(executor, null)</code>. - * - * @param executor the executor to use for each call to - * <code>handleNotification()</code>. - * @since 1.6 - */ - public NotificationBroadcasterSupport(Executor executor) - { - this(executor, (MBeanNotificationInfo) null); - } - - /** - * Constructs a {@link NotificationBroadcasterSupport} using - * the default synchronous dispatch model, where a single - * thread sends the notification to all listeners. The specified - * {@link MBeanNotificationInfo} array is used to provide - * information about the notifications on calls to - * {@link #getNotificationInfo()}, where a clone will be - * returned if the array is non-empty. This is equivalent to - * calling <code>NotificationBroadcasterSupport(null, info)</code>. - * - * @param info an array of {@link MBeanNotificationInfo} objects - * describing the notifications delivered by this - * broadcaster. This may be <code>null</code>, which - * is taken as being equivalent to an empty array. - */ - public NotificationBroadcasterSupport(MBeanNotificationInfo... info) - { - this(null, info); - } - - /** - * Constructs a {@link NotificationBroadcasterSupport} where - * the specified (@link java.util.concurrent.Executor} is used - * to perform each invocation of the - * {@link #handleNotification(NotificationListener, Notification, - * Object)} method. Filtering is performed beforehand, by this - * thread; only calls which have successfully passed through the - * filter are sent to the executor. The specified - * {@link MBeanNotificationInfo} array is used to provide - * information about the notifications on calls to - * {@link #getNotificationInfo()}, where a clone will be - * returned if the array is non-empty. - * - * @param executor the executor to use for each call to - * <code>handleNotification()</code>. - * @param info an array of {@link MBeanNotificationInfo} objects - * describing the notifications delivered by this - * broadcaster. This may be <code>null</code>, which - * is taken as being equivalent to an empty array. - * @since 1.6 - */ - public NotificationBroadcasterSupport(Executor executor, - MBeanNotificationInfo... info) - { - this.executor = executor; - this.info = info; - } - - /** - * Registers the specified listener as a new recipient of - * notifications from this bean. If non-null, the filter - * argument will be used to select which notifications are - * delivered. The supplied object will also be passed to - * the recipient with each notification. This should not - * be modified by the broadcaster, but instead should be - * passed unmodified to the listener. - * - * @param listener the new listener, who will receive - * notifications from this broadcasting bean. - * @param filter a filter to determine which notifications are - * delivered to the listener, or <code>null</code> - * if no filtering is required. - * @param passback an object to be passed to the listener with - * each notification. - * @throws IllegalArgumentException if <code>listener</code> is - * <code>null</code>. - * @see #removeNotificationListener(NotificationListener) - */ - public void addNotificationListener(NotificationListener listener, - NotificationFilter filter, - Object passback) - throws IllegalArgumentException - { - if (listener == null) - throw new IllegalArgumentException("Null listener added to bean."); - listeners.add(new ListenerData(listener, filter, passback)); - } - - /** - * Returns an array describing the notifications this - * bean may send to its registered listeners. Ideally, this - * array should be complete, but in some cases, this may - * not be possible. However, be aware that some listeners - * may expect this to be so. - * - * @return the array of possible notifications. - */ - public MBeanNotificationInfo[] getNotificationInfo() - { - if (info == null || info.length == 0) - return new MBeanNotificationInfo[0]; - return (MBeanNotificationInfo[]) info.clone(); - } - - /** - * This method is called on a per-listener basis, either - * from this thread or the supplied executor, and may be - * overridden by subclasses which wish to change how - * notifications are delivered. The default - * implementation simply calls - * <code>listener.handleNotification(notif, passback)</code>. - * - * @param listener the listener to send the notification to. - * @param notif the notification to dispatch. - * @param passback the passback object of the listener. - */ - protected void handleNotification(NotificationListener listener, - Notification notif, - Object passback) - { - listener.handleNotification(notif, passback); - } - - /** - * Removes the specified listener from the list of recipients - * of notifications from this bean. This includes all combinations - * of filters and passback objects registered for this listener. - * For more specific removal of listeners, see the subinterface - * {@link NotificationEmitter}. - * - * @param listener the listener to remove. - * @throws ListenerNotFoundException if the specified listener - * is not registered with this bean. - * @see #addNotificationListener(NotificationListener, NotificationFilter, - * java.lang.Object) - */ - public void removeNotificationListener(NotificationListener listener) - throws ListenerNotFoundException - { - Iterator<ListenerData> it = listeners.iterator(); - boolean foundOne = false; - while (it.hasNext()) - { - if (it.next().getListener() == listener) - { - it.remove(); - foundOne = true; - } - } - if (!foundOne) - throw new ListenerNotFoundException("The specified listener, " + listener + - "is not registered with this bean."); - } - - /** - * Removes the specified listener from the list of recipients - * of notifications from this bean. Only the first instance with - * the supplied filter and passback object is removed. - * <code>null</code> is used as a valid value for these parameters, - * rather than as a way to remove all registration instances for - * the specified listener; for this behaviour instead, see the details - * of the same method in {@link NotificationBroadcaster}. - * - * @param listener the listener to remove. - * @param filter the filter of the listener to remove. - * @param passback the passback object of the listener to remove. - * @throws ListenerNotFoundException if the specified listener - * is not registered with this bean. - * @see #addNotificationListener(NotificationListener, NotificationFilter, - * java.lang.Object) - */ - public void removeNotificationListener(NotificationListener listener, - NotificationFilter filter, - Object passback) - throws ListenerNotFoundException - { - if (!(listeners.remove(new ListenerData(listener, filter, passback)))) - { - throw new ListenerNotFoundException("The specified listener, " + listener + - " with filter " + filter + - "and passback " + passback + - ", is not registered with this bean."); - } - } - - /** - * <p> - * Performs delivery of the notification. If an executor - * was specified on construction, this will be used to call - * {@link #handleNotification(NotificationListener, Notification, - * Object)}. If the executor is <code>null</code>, however, - * this thread calls the method itself in order to perform a - * synchronous dispatch of the notification to all eligible - * listeners. - * </p> - * <p> - * Prior to either process taking place, the listeners are filtered. - * Notifications are only delivered if the filter is either - * <code>null</code> or returns true from the - * {@link NotificationFilter#isNotificationEnabled(Notification)} - * method. - * </p> - * - * @param notif the notification to send. - */ - public void sendNotification(Notification notif) - { - for (ListenerData ldata : listeners) - { - NotificationFilter filter = ldata.getFilter(); - if (filter == null || filter.isNotificationEnabled(notif)) - { - if (executor == null) - try - { - handleNotification(ldata.getListener(), notif, - ldata.getPassback()); - } - catch (Exception e) { /* Ignore */ } - else - executor.execute(new DispatchTask(ldata, notif)); - } - } - } - - /** - * The dispatch task to be performed by an executor. - */ - private final class DispatchTask - implements Runnable - { - - /** - * The data on the listener being called. - */ - private ListenerData ldata; - - /** - * The notification to send. - */ - private Notification notif; - - /** - * Construct a new {@link DispatchTask}. - * - * @param ldata the listener data. - * @param notif the notification to send. - */ - public DispatchTask(ListenerData ldata, - Notification notif) - { - this.ldata = ldata; - this.notif = notif; - } - - /** - * Dispatch the notification. - */ - public void run() - { - try - { - handleNotification(ldata.getListener(), notif, - ldata.getPassback()); - } - catch (Exception e) { /* Ignore */ } - } - } - -} |