001/**
002 *
003 * Copyright 2020-2021 Florian Schmaus
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smack.filter;
018
019import javax.xml.namespace.QName;
020
021import org.jivesoftware.smack.packet.ExtensionElement;
022import org.jivesoftware.smack.packet.Stanza;
023import org.jivesoftware.smack.packet.XmlElement;
024import org.jivesoftware.smack.util.XmppElementUtil;
025
026public class ExtensionElementFilter<E extends ExtensionElement> implements StanzaFilter {
027
028    private final Class<E> extensionElementClass;
029    private final QName extensionElementQName;
030
031    protected ExtensionElementFilter(Class<E> extensionElementClass) {
032        this.extensionElementClass = extensionElementClass;
033        extensionElementQName = XmppElementUtil.getQNameFor(extensionElementClass);
034    }
035
036    @Override
037    public final boolean accept(Stanza stanza) {
038        XmlElement extensionElement = stanza.getExtension(extensionElementQName);
039        if (extensionElement == null) {
040            return false;
041        }
042
043        if (!extensionElementClass.isInstance(extensionElement)) {
044            return false;
045        }
046
047        E specificExtensionElement = extensionElementClass.cast(extensionElement);
048        return accept(specificExtensionElement);
049    }
050
051    public boolean accept(E extensionElement) {
052        return true;
053    }
054}