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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  package org.apache.logging.log4j.core.pattern;
18  
19  import org.apache.logging.log4j.core.LogEvent;
20  import org.apache.logging.log4j.core.config.plugins.Plugin;
21  import org.apache.logging.log4j.core.impl.ThrowableProxy;
22  import org.apache.logging.log4j.core.util.Constants;
23  
24  /**
25   * Outputs the Throwable portion of the LoggingEvent as a full stack trace
26   * unless this converter's option is 'short', where it just outputs the first line of the trace, or if
27   * the number of lines to print is explicitly specified.
28   * <p>
29   * The extended stack trace will also include the location of where the class was loaded from and the
30   * version of the jar if available.
31   */
32  @Plugin(name = "ExtendedThrowablePatternConverter", category = PatternConverter.CATEGORY)
33  @ConverterKeys({ "xEx", "xThrowable", "xException" })
34  public final class ExtendedThrowablePatternConverter extends ThrowablePatternConverter {
35  
36      /**
37       * Private constructor.
38       *
39       * @param options options, may be null.
40       */
41      private ExtendedThrowablePatternConverter(final String[] options) {
42          super("ExtendedThrowable", "throwable", options);
43      }
44  
45      /**
46       * Gets an instance of the class.
47       *
48       * @param options pattern options, may be null.  If first element is "short",
49       *                only the first line of the throwable will be formatted.
50       * @return instance of class.
51       */
52      public static ExtendedThrowablePatternConverter newInstance(final String[] options) {
53          return new ExtendedThrowablePatternConverter(options);
54      }
55  
56      /**
57       * {@inheritDoc}
58       */
59      @Override
60      public void format(final LogEvent event, final StringBuilder toAppendTo) {
61          final ThrowableProxy proxy = event.getThrownProxy();
62          final Throwable throwable = event.getThrown();
63          if ((throwable != null || proxy != null) && options.anyLines()) {
64              if (proxy == null) {
65                  super.format(event, toAppendTo);
66                  return;
67              }
68              final String extStackTrace = proxy.getExtendedStackTraceAsString(options.getPackages());
69              final int len = toAppendTo.length();
70              if (len > 0 && !Character.isWhitespace(toAppendTo.charAt(len - 1))) {
71                  toAppendTo.append(' ');
72              }
73              if (!options.allLines() || !Constants.LINE_SEPARATOR.equals(options.getSeparator())) {
74                  final StringBuilder sb = new StringBuilder();
75                  final String[] array = extStackTrace.split(Constants.LINE_SEPARATOR);
76                  final int limit = options.minLines(array.length) - 1;
77                  for (int i = 0; i <= limit; ++i) {
78                      sb.append(array[i]);
79                      if (i < limit) {
80                          sb.append(options.getSeparator());
81                      }
82                  }
83                  toAppendTo.append(sb.toString());
84  
85              } else {
86                  toAppendTo.append(extStackTrace);
87              }
88          }
89      }
90  }