NotFilter.java

  1. /**
  2.  *
  3.  * Copyright 2003-2007 Jive Software, 2024 Florian Schmaus.
  4.  *
  5.  * Licensed under the Apache License, Version 2.0 (the "License");
  6.  * you may not use this file except in compliance with the License.
  7.  * You may obtain a copy of the License at
  8.  *
  9.  *     http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */

  17. package org.jivesoftware.smack.filter;

  18. import org.jivesoftware.smack.packet.ExtensionElement;
  19. import org.jivesoftware.smack.packet.Stanza;
  20. import org.jivesoftware.smack.util.Objects;

  21. /**
  22.  * Implements the logical NOT operation on a stanza filter. In other words, packets
  23.  * pass this filter if they do not pass the supplied filter.
  24.  *
  25.  * @author Matt Tucker
  26.  */
  27. public class NotFilter implements StanzaFilter {

  28.     private final StanzaFilter filter;

  29.     /**
  30.      * Creates a NOT filter using the specified filter.
  31.      *
  32.      * @param filter the filter.
  33.      */
  34.     public NotFilter(StanzaFilter filter) {
  35.         this.filter = Objects.requireNonNull(filter, "Parameter must not be null.");
  36.     }

  37.     @Override
  38.     public boolean accept(Stanza packet) {
  39.         return !filter.accept(packet);
  40.     }

  41.     public static <E extends ExtensionElement> NotFilter of(Class<E> extensionElementClass) {
  42.         ExtensionElementFilter<E> extensionElementFilter = new ExtensionElementFilter<>(extensionElementClass);
  43.         return new NotFilter(extensionElementFilter);
  44.     }
  45. }