    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    package org.apache.logging.log4j.core.lookup;
    018
    019    import java.text.DateFormat;
    020    import java.text.SimpleDateFormat;
    021    import java.util.Date;
    022
    023    import org.apache.logging.log4j.Logger;
    024    import org.apache.logging.log4j.Marker;
    025    import org.apache.logging.log4j.MarkerManager;
    026    import org.apache.logging.log4j.core.LogEvent;
    027    import org.apache.logging.log4j.core.config.plugins.Plugin;
    028    import org.apache.logging.log4j.status.StatusLogger;
    029
    030    /**
    031     * Formats the current date or the date in the LogEvent. The "key" is used as the format String.
    032     */
    033    @Plugin(name = "date", category = StrLookup.CATEGORY)
    034    public class DateLookup implements StrLookup {
    035
    036        private static final Logger LOGGER = StatusLogger.getLogger();
    037        private static final Marker LOOKUP = MarkerManager.getMarker("LOOKUP");
    038
    039        /**
    040         * Looks up the value of the environment variable.
    041         * @param key the format to use. If null, the default DateFormat will be used.
    042         * @return The value of the environment variable.
    043         */
    044        @Override
    045        public String lookup(final String key) {
    046            return formatDate(System.currentTimeMillis(), key);
    047        }
    048
    049        /**
    050         * Looks up the value of the environment variable.
    051         * @param event The current LogEvent (is ignored by this StrLookup).
    052         * @param key the format to use. If null, the default DateFormat will be used.
    053         * @return The value of the environment variable.
    054         */
    055        @Override
    056        public String lookup(final LogEvent event, final String key) {
    057            return formatDate(event.getTimeMillis(), key);
    058        }
    059
    060        private String formatDate(final long date, final String format) {
    061            DateFormat dateFormat = null;
    062            if (format != null) {
    063                try {
    064                    dateFormat = new SimpleDateFormat(format);
    065                } catch (final Exception ex) {
    066                    LOGGER.error(LOOKUP, "Invalid date format: [{}], using default", format, ex);
    067                }
    068            }
    069            if (dateFormat == null) {
    070                dateFormat = DateFormat.getInstance();
    071            }
    072            return dateFormat.format(new Date(date));
    073        }
    074    }