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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  import org.apache.logging.log4j.util.PerformanceSensitive;
23  
24  
25  /**
26   * Formats a string literal.
27   */
28  @PerformanceSensitive("allocation") // except for replacements
29  public final class LiteralPatternConverter extends LogEventPatternConverter implements ArrayPatternConverter {
30  
31      /**
32       * String literal.
33       */
34      private final String literal;
35  
36      private final Configuration config;
37  
38      private final boolean substitute;
39  
40      /**
41       * Create a new instance.
42       *
43       * @param config The Configuration.
44       * @param literal string literal.
45       * @param convertBackslashes if {@code true}, backslash characters are treated as escape characters and character
46       *            sequences like "\" followed by "t" (backslash+t) are converted to special characters like '\t' (tab).
47       */
48      public LiteralPatternConverter(final Configuration config, final String literal, final boolean convertBackslashes) {
49          super("Literal", "literal");
50          this.literal = convertBackslashes ? OptionConverter.convertSpecialChars(literal) : literal; // LOG4J2-829
51          this.config = config;
52          substitute = config != null && literal.contains("${");
53      }
54  
55      /**
56       * {@inheritDoc}
57       */
58      @Override
59      public void format(final LogEvent event, final StringBuilder toAppendTo) {
60          toAppendTo.append(substitute ? config.getStrSubstitutor().replace(event, literal) : literal);
61      }
62  
63      /**
64       * {@inheritDoc}
65       */
66      @Override
67      public void format(final Object obj, final StringBuilder output) {
68          output.append(substitute ? config.getStrSubstitutor().replace(literal) : literal);
69      }
70  
71      /**
72       * {@inheritDoc}
73       */
74      @Override
75      public void format(final StringBuilder output, final Object... objects) {
76          output.append(substitute ? config.getStrSubstitutor().replace(literal) : literal);
77      }
78  
79      public String getLiteral() {
80          return literal;
81      }
82  
83      @Override
84      public boolean isVariable() {
85          return false;
86      }
87  
88      @Override
89      public String toString() {
90          return "LiteralPatternConverter[literal=" + literal + ", config=" + config + ", substitute=" + substitute + "]";
91      }
92  
93  }