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 the event sequence number. 025 * 026 * @author Ceki Gülcü 027 */ 028public class SequenceNumberPatternConverter 029 extends LoggingEventPatternConverter { 030 /** 031 * Singleton. 032 */ 033 private static final SequenceNumberPatternConverter INSTANCE = 034 new SequenceNumberPatternConverter(); 035 036 /** 037 * Private constructor. 038 */ 039 private SequenceNumberPatternConverter() { 040 super("Sequence Number", "sn"); 041 } 042 043 /** 044 * Obtains an instance of SequencePatternConverter. 045 * @param options options, currently ignored, may be null. 046 * @return instance of SequencePatternConverter. 047 */ 048 public static SequenceNumberPatternConverter newInstance( 049 final String[] options) { 050 return INSTANCE; 051 } 052 053 /** 054 * {@inheritDoc} 055 */ 056 public void format(final LoggingEvent event, final StringBuffer toAppendTo) { 057 toAppendTo.append("0"); 058 } 059}