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 org.apache.logging.log4j.core.LogEvent;
020    import org.apache.logging.log4j.core.config.plugins.Plugin;
021    
022    
023    /**
024     * Formats a logger name.
025     */
026    @Plugin(name = "LoggerPatternConverter", category = PatternConverter.CATEGORY)
027    @ConverterKeys({ "c", "logger" })
028    public final class LoggerPatternConverter extends NamePatternConverter {
029        /**
030         * Singleton.
031         */
032        private static final LoggerPatternConverter INSTANCE =
033            new LoggerPatternConverter(null);
034    
035        /**
036         * Private constructor.
037         *
038         * @param options options, may be null.
039         */
040        private LoggerPatternConverter(final String[] options) {
041            super("Logger", "logger", options);
042        }
043    
044        /**
045         * Obtains an instance of pattern converter.
046         *
047         * @param options options, may be null.
048         * @return instance of pattern converter.
049         */
050        public static LoggerPatternConverter newInstance(
051            final String[] options) {
052            if (options == null || options.length == 0) {
053                return INSTANCE;
054            }
055    
056            return new LoggerPatternConverter(options);
057        }
058    
059        /**
060         * {@inheritDoc}
061         */
062        @Override
063        public void format(final LogEvent event, final StringBuilder toAppendTo) {
064            toAppendTo.append(abbreviate(event.getLoggerName()));
065        }
066    }