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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.layout;
18  
19  import java.nio.charset.Charset;
20  import java.nio.charset.StandardCharsets;
21  
22  import org.apache.logging.log4j.core.LogEvent;
23  
24  /**
25   * Abstract base class for Layouts that result in a String.
26   */
27  public abstract class AbstractStringLayout extends AbstractLayout<String> {
28  
29      private static final long serialVersionUID = 1L;
30  
31      /**
32       * Converts a String to a byte[].
33       * 
34       * @param str
35       *            if null, return null.
36       * @param charset
37       *            if null, use the default charset.
38       * @return a byte[]
39       */
40      static byte[] toBytes(final String str, final Charset charset) {
41          if (str != null) {
42              return str.getBytes(charset != null ? charset : Charset.defaultCharset());
43          }
44          return null;
45      }
46  
47      /**
48       * The charset for the formatted message.
49       */
50      // TODO: Charset is not serializable. Implement read/writeObject() ?
51      private final Charset charset;
52  
53      protected AbstractStringLayout(final Charset charset) {
54          this(charset, null, null);
55      }
56  
57      protected AbstractStringLayout(final Charset charset, final byte[] header, final byte[] footer) {
58          super(header, footer);
59          this.charset = charset == null ? StandardCharsets.UTF_8 : charset;
60      }
61  
62      protected byte[] getBytes(final String s) {
63          return s.getBytes(charset);
64      }
65  
66      protected Charset getCharset() {
67          return charset;
68      }
69  
70      /**
71       * @return The default content type for Strings.
72       */
73      @Override
74      public String getContentType() {
75          return "text/plain";
76      }
77  
78      /**
79       * Formats the Log Event as a byte array.
80       *
81       * @param event
82       *        The Log Event.
83       * @return The formatted event as a byte array.
84       */
85      @Override
86      public byte[] toByteArray(final LogEvent event) {
87          return toSerializable(event).getBytes(charset);
88      }
89  
90  }