View Javadoc

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 org.apache.logging.log4j.core.LogEvent;
20  
21  import java.io.UnsupportedEncodingException;
22  import java.nio.charset.Charset;
23  
24  /**
25   * Abstract base class for Layouts that result in a String.
26   */
27  public abstract class AbstractStringLayout extends AbstractLayout<String> {
28  
29      /**
30       * The charset of the formatted message.
31       */
32      private final Charset charset;
33  
34      private final StringEncoder encoder;
35  
36      protected AbstractStringLayout(Charset charset) {
37          this.charset = charset;
38          boolean useClass = false;
39          try {
40              if (String.class.getMethod("getBytes", new Class[] {Charset.class}) != null) {
41                  useClass = true;
42              }
43          } catch (NoSuchMethodException ex) {
44              // Not JDK 6 or greater.
45          }
46          encoder = useClass ? new ClassEncoder() : new NameEncoder();
47      }
48  
49      /**
50       * Formats the Log Event as a byte array.
51       *
52       * @param event The Log Event.
53       * @return The formatted event as a byte array.
54       */
55      public byte[] toByteArray(LogEvent event) {
56          return encoder.getBytes(toSerializable(event));
57      }
58  
59      protected Charset getCharset() {
60          return charset;
61      }
62  
63      /**
64       * Encoder interface to support Java 5 and Java 6+.
65       */
66      private interface StringEncoder {
67  
68          byte[] getBytes(String str);
69      }
70  
71      /**
72       * JDK 6 or greater.
73       */
74      private class ClassEncoder implements StringEncoder {
75          public byte[] getBytes(String str) {
76              return str.getBytes(charset);
77          }
78      }
79  
80      /**
81       * JDK 5.
82       */
83      private class NameEncoder implements StringEncoder {
84          public byte[] getBytes(String str) {
85              try {
86                  return str.getBytes(charset.name());
87              } catch (UnsupportedEncodingException ex) {
88                  // This shouldn't ever happen since an invalid Charset would never have been created.
89                  return str.getBytes();
90              }
91          }
92      }
93  }