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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.LocationInfo;
21  import org.apache.log4j.spi.LoggingEvent;
22  
23  
24  /**
25   * Return the event's line location information in a StringBuffer.
26   *
27   * @author Ceki Gülcü
28   */
29  public final class LineLocationPatternConverter
30    extends LoggingEventPatternConverter {
31    /**
32     * Singleton.
33     */
34    private static final LineLocationPatternConverter INSTANCE =
35      new LineLocationPatternConverter();
36  
37    /**
38     * Private constructor.
39     */
40    private LineLocationPatternConverter() {
41      super("Line", "line");
42    }
43  
44    /**
45     * Obtains an instance of pattern converter.
46     * @param options options, may be null.
47     * @return instance of pattern converter.
48     */
49    public static LineLocationPatternConverter newInstance(
50      final String[] options) {
51      return INSTANCE;
52    }
53  
54    /**
55     * {@inheritDoc}
56     */
57    public void format(final LoggingEvent event, final StringBuffer output) {
58      LocationInfo locationInfo = event.getLocationInformation();
59  
60      if (locationInfo != null) {
61        output.append(locationInfo.getLineNumber());
62      }
63    }
64  }