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     * Returns the event's line location information in a StringBuilder.
024     */
025    @Plugin(name = "LineLocationPatternConverter", category = PatternConverter.CATEGORY)
026    @ConverterKeys({ "L", "line" })
027    public final class LineLocationPatternConverter extends LogEventPatternConverter {
028        /**
029         * Singleton.
030         */
031        private static final LineLocationPatternConverter INSTANCE =
032            new LineLocationPatternConverter();
033    
034        /**
035         * Private constructor.
036         */
037        private LineLocationPatternConverter() {
038            super("Line", "line");
039        }
040    
041        /**
042         * Obtains an instance of pattern converter.
043         *
044         * @param options options, may be null.
045         * @return instance of pattern converter.
046         */
047        public static LineLocationPatternConverter newInstance(
048            final String[] options) {
049            return INSTANCE;
050        }
051    
052        /**
053         * {@inheritDoc}
054         */
055        @Override
056        public void format(final LogEvent event, final StringBuilder output) {
057            final StackTraceElement element = event.getSource();
058    
059            if (element != null) {
060                output.append(element.getLineNumber());
061            }
062        }
063    }