AttributeChangeNotificationFilter.java

/* AttributeChangeNotificationFilter.java -- Filter on attribute name
   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 java.io.Serializable;

import java.util.Vector;

/**
 * Performs filtering of {@link AttributeChangeNotification}s
 * based on a list of attribute names.
 *
 * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
 * @since 1.5
 */
public class AttributeChangeNotificationFilter
  implements NotificationFilter, Serializable
{

  /**
   * Compatible with JDK 1.5
   */
  private static final long serialVersionUID = -6347317584796410029L;

  /**
   * Lists the names of the attributes that may pass
   * through the filter.
   */
  private final Vector<String> enabledAttributes = new Vector<String>();

  /**
   * Blocks all {@link AttributeChangeNotification}s
   * by emptying the list of enabled attributes.
   */
  public void disableAllAttributes()
  {
    enabledAttributes.clear();
  }

  /**
   * Removes the specified attribute name from the list
   * of enabled attributes, thus preventing
   * {@link AttributeChangeNotification}s for this attribute
   * from passing through the filter.  If the attribute is
   * not enabled, this has no effect.
   *
   * @param name the name of the attribute to disable.
   */
  public void disableAttribute(String name)
  {
    enabledAttributes.remove(name);
  }

  /**
   * Adds the specified attribute name to the list
   * of enabled attributes, thus allowing
   * {@link AttributeChangeNotification}s for this attribute
   * to pass through the filter.  If the attribute is
   * enabled, this has no effect.
   *
   * @param name the name of the attribute to enable.
   */
  public void enableAttribute(String name)
  {
    if (!enabledAttributes.contains(name))
      enabledAttributes.add(name);
  }
  
  /**
   * Returns the list of enabled attributes for this
   * filter.
   *
   * @return the list of enabled attributes.
   */
  public Vector<String> getEnabledAttributes()
  {
    return enabledAttributes;
  }

  /**
   * Returns true if the specified notification is an
   * {@link AttributeChangeNotification} and the name of the
   * attribute concerned is in the list of enabled attributes
   * for this filter.
   *
   * @param notif the notification being filtered.
   * @return true if the notification is an
   *         {@link AttributeChangeNotification} for an
   *         enabled attribute.
   */
  public boolean isNotificationEnabled(Notification notif)
  {
    if (notif instanceof AttributeChangeNotification)
      {
	AttributeChangeNotification n =
	  (AttributeChangeNotification) notif;
	return enabledAttributes.contains(n.getAttributeName());
      }
    return false;
  }

}