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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.helpers.Constants;
22  import org.apache.logging.log4j.core.impl.Log4jLogEvent;
23  import org.apache.logging.log4j.core.impl.ThrowableProxy;
24  
25  /**
26   * Outputs the Throwable portion of the LoggingEvent as a full stacktrace
27   * unless this converter's option is 'short', where it just outputs the first line of the trace, or if
28   * the number of lines to print is explicitly specified.
29   * <p>
30   * The extended stack trace will also include the location of where the class was loaded from and the
31   * version of the jar if available.
32   */
33  @Plugin(name = "RootThrowablePatternConverter", category = "Converter")
34  @ConverterKeys({"rEx", "rThrowable", "rException" })
35  public final class RootThrowablePatternConverter extends ThrowablePatternConverter {
36  
37      /**
38       * Private constructor.
39       *
40       * @param options options, may be null.
41       */
42      private RootThrowablePatternConverter(final String[] options) {
43          super("RootThrowable", "throwable", options);
44      }
45  
46      /**
47       * Gets an instance of the class.
48       *
49       * @param options pattern options, may be null.  If first element is "short",
50       *                only the first line of the throwable will be formatted.
51       * @return instance of class.
52       */
53      public static RootThrowablePatternConverter newInstance(final String[] options) {
54          return new RootThrowablePatternConverter(options);
55      }
56  
57      /**
58       * {@inheritDoc}
59       */
60      @Override
61      public void format(final LogEvent event, final StringBuilder toAppendTo) {
62          ThrowableProxy proxy = null;
63          if (event instanceof Log4jLogEvent) {
64              proxy = ((Log4jLogEvent) event).getThrownProxy();
65          }
66          final Throwable throwable = event.getThrown();
67          if (throwable != null && options.anyLines()) {
68              if (proxy == null) {
69                  super.format(event, toAppendTo);
70                  return;
71              }
72              final String trace = proxy.getRootCauseStackTrace(options.getPackages());
73              final int len = toAppendTo.length();
74              if (len > 0 && !Character.isWhitespace(toAppendTo.charAt(len - 1))) {
75                  toAppendTo.append(" ");
76              }
77              if (!options.allLines() || !Constants.LINE_SEP.equals(options.getSeparator())) {
78                  final StringBuilder sb = new StringBuilder();
79                  final String[] array = trace.split(Constants.LINE_SEP);
80                  final int limit = options.minLines(array.length) - 1;
81                  for (int i = 0; i <= limit; ++i) {
82                      sb.append(array[i]);
83                      if (i < limit) {
84                          sb.append(options.getSeparator());
85                      }
86                  }
87                  toAppendTo.append(sb.toString());
88  
89              } else {
90                  toAppendTo.append(trace);
91              }
92          }
93      }
94  }