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Commons Modeler example source code file (BaseNotificationBroadcaster.java)

This example Commons Modeler source code file (BaseNotificationBroadcaster.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Commons Modeler tags/keywords

arraylist, baseattributefilter, baseattributefilter, basenotificationbroadcasterentry, basenotificationbroadcasterentry, iterator, listenernotfoundexception, management, mbeannotificationinfo, notificationfilter, notificationfilter, notificationlistener, object, object, string, util

The Commons Modeler BaseNotificationBroadcaster.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


package org.apache.commons.modeler;


import java.util.ArrayList;
import java.util.Iterator;

import javax.management.ListenerNotFoundException;
import javax.management.MBeanNotificationInfo;
import javax.management.Notification;
import javax.management.NotificationBroadcaster;
import javax.management.NotificationFilter;
import javax.management.NotificationListener;


/**
 * <p>Implementation of NotificationBroadcaster for attribute
 * change notifications.  This class is used by <code>BaseModelMBean to
 * handle notifications of attribute change events to interested listeners.
 *</p>
 *
 * @author Craig R. McClanahan
 * @author Costin Manolache
 */

public class BaseNotificationBroadcaster implements NotificationBroadcaster {


    // ----------------------------------------------------------- Constructors


    // ----------------------------------------------------- Instance Variables


    /**
     * The set of registered <code>BaseNotificationBroadcasterEntry
     * entries.
     */
    protected ArrayList entries = new ArrayList();


    // --------------------------------------------------------- Public Methods


    /**
     * Add a notification event listener to this MBean.
     *
     * @param listener Listener that will receive event notifications
     * @param filter Filter object used to filter event notifications
     *  actually delivered, or <code>null for no filtering
     * @param handback Handback object to be sent along with event
     *  notifications
     *
     * @exception IllegalArgumentException if the listener parameter is null
     */
    public void addNotificationListener(NotificationListener listener,
                                        NotificationFilter filter,
                                        Object handback)
        throws IllegalArgumentException {

        synchronized (entries) {

            // Optimization to coalesce attribute name filters
            if (filter instanceof BaseAttributeFilter) {
                BaseAttributeFilter newFilter = (BaseAttributeFilter) filter;
                Iterator items = entries.iterator();
                while (items.hasNext()) {
                    BaseNotificationBroadcasterEntry item =
                        (BaseNotificationBroadcasterEntry) items.next();
                    if ((item.listener == listener) &&
                        (item.filter != null) &&
                        (item.filter instanceof BaseAttributeFilter) &&
                        (item.handback == handback)) {
                        BaseAttributeFilter oldFilter =
                            (BaseAttributeFilter) item.filter;
                        String newNames[] = newFilter.getNames();
                        String oldNames[] = oldFilter.getNames();
                        if (newNames.length == 0) {
                            oldFilter.clear();
                        } else {
                            if (oldNames.length != 0) {
                                for (int i = 0; i < newNames.length; i++)
                                    oldFilter.addAttribute(newNames[i]);
                            }
                        }
                        return;
                    }
                }
            }

            // General purpose addition of a new entry
            entries.add(new BaseNotificationBroadcasterEntry
                        (listener, filter, handback));
        }

    }


    /**
     * Return an <code>MBeanNotificationInfo object describing the
     * notifications sent by this MBean.
     */
    public MBeanNotificationInfo[] getNotificationInfo() {

        return (new MBeanNotificationInfo[0]);

    }


    /**
     * Remove a notification event listener from this MBean.
     *
     * @param listener The listener to be removed (any and all registrations
     *  for this listener will be eliminated)
     *
     * @exception ListenerNotFoundException if this listener is not
     *  registered in the MBean
     */
    public void removeNotificationListener(NotificationListener listener)
        throws ListenerNotFoundException {

        synchronized (entries) {
            Iterator items = entries.iterator();
            while (items.hasNext()) {
                BaseNotificationBroadcasterEntry item =
                    (BaseNotificationBroadcasterEntry) items.next();
                if (item.listener == listener)
                    items.remove();
            }
        }

    }


    /**
     * Remove a notification event listener from this MBean.
     *
     * @param listener The listener to be removed (any and all registrations
     *  for this listener will be eliminated)
     * @param handback Handback object to be sent along with event
     *  notifications
     *
     * @exception ListenerNotFoundException if this listener is not
     *  registered in the MBean
     */
    public void removeNotificationListener(NotificationListener listener,
                                           Object handback)
        throws ListenerNotFoundException {

        removeNotificationListener(listener);

    }


    /**
     * Remove a notification event listener from this MBean.
     *
     * @param listener The listener to be removed (any and all registrations
     *  for this listener will be eliminated)
     * @param filter Filter object used to filter event notifications
     *  actually delivered, or <code>null for no filtering
     * @param handback Handback object to be sent along with event
     *  notifications
     *
     * @exception ListenerNotFoundException if this listener is not
     *  registered in the MBean
     */
    public void removeNotificationListener(NotificationListener listener,
                                           NotificationFilter filter,
                                           Object handback)
        throws ListenerNotFoundException {

        removeNotificationListener(listener);

    }


    /**
     * Send the specified notification to all interested listeners.
     *
     * @param notification The notification to be sent
     */
    public void sendNotification(Notification notification) {

        synchronized (entries) {
            Iterator items = entries.iterator();
            while (items.hasNext()) {
                BaseNotificationBroadcasterEntry item =
                    (BaseNotificationBroadcasterEntry) items.next();
                if ((item.filter != null) &&
                    (!item.filter.isNotificationEnabled(notification)))
                    continue;
                item.listener.handleNotification(notification, item.handback);
            }
        }

    }


    // -------------------- Internal Extensions   --------------------

    // Fast access. First index is the hook type
    // ( FixedNotificationFilter.getType() ).
    NotificationListener hooks[][]=new NotificationListener[20][];
    int hookCount[]=new int[20];

    private synchronized void registerNotifications( FixedNotificationFilter filter ) {
        String names[]=filter.getNames();
        Registry reg=Registry.getRegistry();
        for( int i=0; i<names.length; i++ ) {
            int code=reg.getId(null, names[i]);
            if( hooks.length < code ) {
                // XXX reallocate
                throw new RuntimeException( "Too many hooks " + code );
            }
            NotificationListener listeners[]=hooks[code];
            if( listeners== null ) {

            }


        }
    }

}


/**
 * Utility class representing a particular registered listener entry.
 */

class BaseNotificationBroadcasterEntry {

    public BaseNotificationBroadcasterEntry(NotificationListener listener,
                                            NotificationFilter filter,
                                            Object handback) {
        this.listener = listener;
        this.filter = filter;
        this.handback = handback;
    }

    public NotificationFilter filter = null;

    public Object handback = null;

    public NotificationListener listener = null;

}

Other Commons Modeler examples (source code examples)

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