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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.util.OptionConverter;
22  
23  
24  /**
25   * Formats a string literal.
26   */
27  public final class LiteralPatternConverter extends LogEventPatternConverter implements ArrayPatternConverter {
28      
29      /**
30       * String literal.
31       */
32      private final String literal;
33  
34      private final Configuration config;
35  
36      private final boolean substitute;
37  
38      /**
39       * Create a new instance.
40       *
41       * @param config The Configuration.
42       * @param literal string literal.
43       * @param convertBackslashes if {@code true}, backslash characters are treated as escape characters and character
44       *            sequences like "\" followed by "t" (backslash+t) are converted to special characters like '\t' (tab).
45       */
46      public LiteralPatternConverter(final Configuration config, final String literal, final boolean convertBackslashes) {
47          super("Literal", "literal");
48          this.literal = convertBackslashes ? OptionConverter.convertSpecialChars(literal) : literal; // LOG4J2-829
49          this.config = config;
50          substitute = config != null && literal.contains("${");
51      }
52  
53      /**
54       * {@inheritDoc}
55       */
56      @Override
57      public void format(final LogEvent event, final StringBuilder toAppendTo) {
58          toAppendTo.append(substitute ? config.getStrSubstitutor().replace(event, literal) : literal);
59      }
60      
61      /**
62       * {@inheritDoc}
63       */
64      @Override
65      public void format(final Object obj, final StringBuilder output) {
66          output.append(substitute ? config.getStrSubstitutor().replace(literal) : literal);
67      }
68  
69      /**
70       * {@inheritDoc}
71       */
72      @Override
73      public void format(final StringBuilder output, final Object... objects) {
74          output.append(substitute ? config.getStrSubstitutor().replace(literal) : literal);
75      }
76  
77      public String getLiteral() {
78          return literal;
79      }
80  
81      @Override
82      public boolean isVariable() {
83          return false;
84      }
85  
86      @Override
87      public String toString() {
88          return "LiteralPatternConverter[literal=" + literal + ", config=" + config + ", substitute=" + substitute + "]";
89      }
90      
91  }