001    /* AttributeChangeNotificationFilter.java -- Filter on attribute name
002       Copyright (C) 2007 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 java.io.Serializable;
041    
042    import java.util.Vector;
043    
044    /**
045     * Performs filtering of {@link AttributeChangeNotification}s
046     * based on a list of attribute names.
047     *
048     * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
049     * @since 1.5
050     */
051    public class AttributeChangeNotificationFilter
052      implements NotificationFilter, Serializable
053    {
054    
055      /**
056       * Compatible with JDK 1.5
057       */
058      private static final long serialVersionUID = -6347317584796410029L;
059    
060      /**
061       * Lists the names of the attributes that may pass
062       * through the filter.
063       */
064      private final Vector<String> enabledAttributes = new Vector<String>();
065    
066      /**
067       * Blocks all {@link AttributeChangeNotification}s
068       * by emptying the list of enabled attributes.
069       */
070      public void disableAllAttributes()
071      {
072        enabledAttributes.clear();
073      }
074    
075      /**
076       * Removes the specified attribute name from the list
077       * of enabled attributes, thus preventing
078       * {@link AttributeChangeNotification}s for this attribute
079       * from passing through the filter.  If the attribute is
080       * not enabled, this has no effect.
081       *
082       * @param name the name of the attribute to disable.
083       */
084      public void disableAttribute(String name)
085      {
086        enabledAttributes.remove(name);
087      }
088    
089      /**
090       * Adds the specified attribute name to the list
091       * of enabled attributes, thus allowing
092       * {@link AttributeChangeNotification}s for this attribute
093       * to pass through the filter.  If the attribute is
094       * enabled, this has no effect.
095       *
096       * @param name the name of the attribute to enable.
097       */
098      public void enableAttribute(String name)
099      {
100        if (!enabledAttributes.contains(name))
101          enabledAttributes.add(name);
102      }
103    
104      /**
105       * Returns the list of enabled attributes for this
106       * filter.
107       *
108       * @return the list of enabled attributes.
109       */
110      public Vector<String> getEnabledAttributes()
111      {
112        return enabledAttributes;
113      }
114    
115      /**
116       * Returns true if the specified notification is an
117       * {@link AttributeChangeNotification} and the name of the
118       * attribute concerned is in the list of enabled attributes
119       * for this filter.
120       *
121       * @param notif the notification being filtered.
122       * @return true if the notification is an
123       *         {@link AttributeChangeNotification} for an
124       *         enabled attribute.
125       */
126      public boolean isNotificationEnabled(Notification notif)
127      {
128        if (notif instanceof AttributeChangeNotification)
129          {
130            AttributeChangeNotification n =
131              (AttributeChangeNotification) notif;
132            return enabledAttributes.contains(n.getAttributeName());
133          }
134        return false;
135      }
136    
137    }