001/* AttributeChangeNotificationFilter.java -- Filter on attribute name
002   Copyright (C) 2007 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 java.io.Serializable;
041
042import 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 */
051public 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}