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(final 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 (final 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(final LogEvent event) {
56 return encoder.getBytes(toSerializable(event));
57 }
58
59 /**
60 * @return The default content type for Strings.
61 */
62 public String getContentType() {
63 return "text/plain";
64 }
65
66 protected Charset getCharset() {
67 return charset;
68 }
69
70 /**
71 * Encoder interface to support Java 5 and Java 6+.
72 */
73 private interface StringEncoder {
74
75 byte[] getBytes(String str);
76 }
77
78 /**
79 * JDK 6 or greater.
80 */
81 private class ClassEncoder implements StringEncoder {
82 public byte[] getBytes(final String str) {
83 return str.getBytes(charset);
84 }
85 }
86
87 /**
88 * JDK 5.
89 */
90 private class NameEncoder implements StringEncoder {
91 public byte[] getBytes(final String str) {
92 try {
93 return str.getBytes(charset.name());
94 } catch (final UnsupportedEncodingException ex) {
95 // This shouldn't ever happen since an invalid Charset would never have been created.
96 return str.getBytes();
97 }
98 }
99 }
100 }