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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.Configuration;
21  import org.apache.logging.log4j.core.config.plugins.Plugin;
22  import org.apache.logging.log4j.core.impl.ThrowableProxy;
23  import org.apache.logging.log4j.util.Strings;
24  
25  /**
26   * Outputs the Throwable portion of the LoggingEvent as a full stack trace
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 = PatternConverter.CATEGORY)
34  @ConverterKeys({ "rEx", "rThrowable", "rException" })
35  public final class RootThrowablePatternConverter extends ThrowablePatternConverter {
36  
37      /**
38       * Private constructor.
39       *
40       * @param config
41       * @param options options, may be null.
42       */
43      private RootThrowablePatternConverter(final Configuration config, final String[] options) {
44          super("RootThrowable", "throwable", options, config);
45      }
46  
47      /**
48       * Gets an instance of the class.
49       *
50       * @param config
51       * @param options pattern options, may be null.  If first element is "short",
52       *                only the first line of the throwable will be formatted.
53       * @return instance of class.
54       */
55      public static RootThrowablePatternConverter newInstance(final Configuration config, final String[] options) {
56          return new RootThrowablePatternConverter(config, options);
57      }
58  
59      /**
60       * {@inheritDoc}
61       */
62      @Override
63      public void format(final LogEvent event, final StringBuilder toAppendTo) {
64          final ThrowableProxy proxy = event.getThrownProxy();
65          final Throwable throwable = event.getThrown();
66          if (throwable != null && options.anyLines()) {
67              if (proxy == null) {
68                  super.format(event, toAppendTo);
69                  return;
70              }
71              final String trace = proxy.getCauseStackTraceAsString(options.getIgnorePackages(), options.getTextRenderer(), getSuffix(event), options.getSeparator());
72              final int len = toAppendTo.length();
73              if (len > 0 && !Character.isWhitespace(toAppendTo.charAt(len - 1))) {
74                  toAppendTo.append(' ');
75              }
76              if (!options.allLines() || !Strings.LINE_SEPARATOR.equals(options.getSeparator())) {
77                  final StringBuilder sb = new StringBuilder();
78                  final String[] array = trace.split(Strings.LINE_SEPARATOR);
79                  final int limit = options.minLines(array.length) - 1;
80                  for (int i = 0; i <= limit; ++i) {
81                      sb.append(array[i]);
82                      if (i < limit) {
83                          sb.append(options.getSeparator());
84                      }
85                  }
86                  toAppendTo.append(sb.toString());
87  
88              } else {
89                  toAppendTo.append(trace);
90              }
91          }
92      }
93  }