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.log4j.pattern;
019
020import org.apache.log4j.spi.LoggingEvent;
021
022
023/**
024 * Formats a logger name.
025 *
026 * @author Ceki Gülcü
027 *
028 */
029public final class LoggerPatternConverter extends NamePatternConverter {
030  /**
031   * Singleton.
032   */
033  private static final LoggerPatternConverter INSTANCE =
034    new LoggerPatternConverter(null);
035
036  /**
037   * Private constructor.
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   * @param options options, may be null.
047   * @return instance of pattern converter.
048   */
049  public static LoggerPatternConverter newInstance(
050    final String[] options) {
051    if ((options == null) || (options.length == 0)) {
052      return INSTANCE;
053    }
054
055    return new LoggerPatternConverter(options);
056  }
057
058  /**
059   * {@inheritDoc}
060   */
061  public void format(final LoggingEvent event, final StringBuffer toAppendTo) {
062    final int initialLength = toAppendTo.length();
063    toAppendTo.append(event.getLoggerName());
064    abbreviate(initialLength, toAppendTo);
065  }
066}