1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.log4j.pattern; 19 20 import org.apache.log4j.spi.LoggingEvent; 21 22 23 /** 24 * Formats the event sequence number. 25 * 26 * @author Ceki Gülcü 27 */ 28 public class SequenceNumberPatternConverter 29 extends LoggingEventPatternConverter { 30 /** 31 * Singleton. 32 */ 33 private static final SequenceNumberPatternConverter INSTANCE = 34 new SequenceNumberPatternConverter(); 35 36 /** 37 * Private constructor. 38 */ 39 private SequenceNumberPatternConverter() { 40 super("Sequence Number", "sn"); 41 } 42 43 /** 44 * Obtains an instance of SequencePatternConverter. 45 * @param options options, currently ignored, may be null. 46 * @return instance of SequencePatternConverter. 47 */ 48 public static SequenceNumberPatternConverter newInstance( 49 final String[] options) { 50 return INSTANCE; 51 } 52 53 /** 54 * {@inheritDoc} 55 */ 56 public void format(final LoggingEvent event, final StringBuffer toAppendTo) { 57 toAppendTo.append("0"); 58 } 59 }