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.pattern;
018    
019    import java.util.UUID;
020    
021    import org.apache.logging.log4j.core.LogEvent;
022    import org.apache.logging.log4j.core.config.plugins.Plugin;
023    import org.apache.logging.log4j.core.util.UuidUtil;
024    
025    /**
026     * Formats the event sequence number.
027     */
028    @Plugin(name = "UuidPatternConverter", category = PatternConverter.CATEGORY)
029    @ConverterKeys({ "u", "uuid" })
030    public final class UuidPatternConverter extends LogEventPatternConverter {
031    
032        private final boolean isRandom;
033    
034        /**
035         * Private constructor.
036         */
037        private UuidPatternConverter(final boolean isRandom) {
038            super("u", "uuid");
039            this.isRandom = isRandom;
040        }
041    
042        /**
043         * Obtains an instance of SequencePatternConverter.
044         *
045         * @param options options, currently ignored, may be null.
046         * @return instance of SequencePatternConverter.
047         */
048        public static UuidPatternConverter newInstance(final String[] options) {
049            if (options.length == 0) {
050                return new UuidPatternConverter(false);
051            }
052    
053            if (options.length > 1 || (!options[0].equalsIgnoreCase("RANDOM") && !options[0].equalsIgnoreCase("Time"))) {
054                LOGGER.error("UUID Pattern Converter only accepts a single option with the value \"RANDOM\" or \"TIME\"");
055            }
056            return new UuidPatternConverter(options[0].equalsIgnoreCase("RANDOM"));
057        }
058    
059        /**
060         * {@inheritDoc}
061         */
062        @Override
063        public void format(final LogEvent event, final StringBuilder toAppendTo) {
064            final UUID uuid = isRandom ? UUID.randomUUID() : UuidUtil.getTimeBasedUuid();
065            toAppendTo.append(uuid.toString());
066        }
067    }