001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. 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 */
017
018package org.apache.logging.log4j.core.lookup;
019
020import org.apache.logging.log4j.Marker;
021import org.apache.logging.log4j.MarkerManager;
022import org.apache.logging.log4j.core.LogEvent;
023import org.apache.logging.log4j.core.config.plugins.Plugin;
024
025/**
026 * Looks-up markers.
027 * 
028 * @since 2.4
029 */
030@Plugin(name = "marker", category = StrLookup.CATEGORY)
031public class MarkerLookup extends AbstractLookup {
032
033    static final String MARKER = "marker";
034
035    @Override
036    public String lookup(final LogEvent event, final String key) {
037        final Marker marker = event == null ? null : event.getMarker();
038        return marker == null ? null : marker.getName();
039    }
040
041    @Override
042    public String lookup(final String key) {
043        return MarkerManager.exists(key) ? key : null;
044    }
045
046}