001/* NotificationFilterSupport.java -- Filter on notification type.
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.util.Vector;
041
042/**
043 * Performs filtering of {@link Notification}s
044 * based on a list of type prefixes.  The type of a notification
045 * is compared with each member of the list using
046 * {@link String#startsWith(String)} and, if one matches,
047 * the notification is allowed to pass through the filter.
048 * Matching on the beginning of the string is used in
049 * preference to wildcards, so <code>type.*</code> will
050 * match only notifications with a type beginning with
051 * code>type.*</code>, not <code>type.</code> as
052 * expected.
053 *
054 * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
055 * @since 1.5
056 */
057public class NotificationFilterSupport
058  implements NotificationFilter
059{
060
061  /**
062   * Compatible with JDK 1.5
063   */
064  private static final long serialVersionUID = 6579080007561786969L;
065
066  /**
067   * Lists the types that may pass through the filter.
068   */
069  private final Vector<String> enabledTypes = new Vector<String>();
070
071  /**
072   * Blocks all types by emptying the list of enabled attributes.
073   */
074  public void disableAllTypes()
075  {
076    enabledTypes.clear();
077  }
078
079  /**
080   * Removes the specified type prefix from the list
081   * of enabled types, thus preventing matching types
082   * from passing through the filter.  If the specified
083   * type prefix is not enabled, this operation has no
084   * effect.
085   *
086   * @param prefix the prefix to disable.
087   */
088  public void disableType(String prefix)
089  {
090    enabledTypes.remove(prefix);
091  }
092
093  /**
094   * Adds the specified type prefix to the list
095   * of enabled types, thus allowing
096   * types starting with this string to pass through
097   * the filter.  If the type prefix is already
098   * enabled, this has no effect.
099   *
100   * @param prefix the prefix to enable.
101   * @throws IllegalArgumentException if <code>prefix</code>
102   *                                  is <code>null</code>.
103   */
104  public void enableType(String prefix)
105  {
106    if (prefix == null)
107      throw new IllegalArgumentException("A null prefix was supplied.");
108    if (!enabledTypes.contains(prefix))
109      enabledTypes.add(prefix);
110  }
111
112  /**
113   * Returns the list of enabled types for this
114   * filter.
115   *
116   * @return the list of enabled types.
117   */
118  public Vector<String> getEnabledTypes()
119  {
120    return enabledTypes;
121  }
122
123  /**
124   * Returns true if the type of the specified notification
125   * begins with one of the enabled type prefixes.
126   *
127   * @param notif the notification being filtered.
128   * @return true if the notification's type is enabled.
129   */
130  public boolean isNotificationEnabled(Notification notif)
131  {
132    String nType = notif.getType();
133    for (String type : enabledTypes)
134      if (nType.startsWith(type))
135        return true;
136    return false;
137  }
138
139}