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 }