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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  
18  package org.apache.commons.codec;
19  
20  import java.nio.charset.Charset;
21  import java.nio.charset.StandardCharsets;
22  
23  /**
24   * Character encoding names required of every implementation of the Java platform.
25   *
26   * From the Java documentation for {@link Charset}:
27   * <p>
28   * <cite>Every implementation of the Java platform is required to support the following character encodings. Consult the
29   * release documentation for your implementation to see if any other encodings are supported. Consult the release
30   * documentation for your implementation to see if any other encodings are supported.</cite>
31   * </p>
32   *
33   * <ul>
34   * <li>{@code US-ASCII}<p>
35   * Seven-bit ASCII, a.k.a. ISO646-US, a.k.a. the Basic Latin block of the Unicode character set.</p></li>
36   * <li>{@code ISO-8859-1}<p>
37   * ISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1.</p></li>
38   * <li>{@code UTF-8}<p>
39   * Eight-bit Unicode Transformation Format.</p></li>
40   * <li>{@code UTF-16BE}<p>
41   * Sixteen-bit Unicode Transformation Format, big-endian byte order.</p></li>
42   * <li>{@code UTF-16LE}<p>
43   * Sixteen-bit Unicode Transformation Format, little-endian byte order.</p></li>
44   * <li>{@code UTF-16}<p>
45   * Sixteen-bit Unicode Transformation Format, byte order specified by a mandatory initial byte-order mark (either order
46   * accepted on input, big-endian used on output.)</p></li>
47   * </ul>
48   *
49   * This perhaps would best belong in the [lang] project. Even if a similar interface is defined in [lang], it is not
50   * foreseen that [codec] would be made to depend on [lang].
51   *
52   * <p>
53   * This class is immutable and thread-safe.
54   * </p>
55   *
56   * @see Charset
57   * @since 1.4
58   */
59  public class CharEncoding {
60  
61      /**
62       * CharEncodingISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1.
63       * <p>
64       * Every implementation of the Java platform is required to support this character encoding.
65       * </p>
66       *
67       * @see Charset
68       */
69      public static final String ISO_8859_1 = StandardCharsets.ISO_8859_1.name();
70  
71      /**
72       * Seven-bit ASCII, also known as ISO646-US, also known as the Basic Latin block of the Unicode character set.
73       * <p>
74       * Every implementation of the Java platform is required to support this character encoding.
75       * </p>
76       *
77       * @see Charset
78       */
79      public static final String US_ASCII = StandardCharsets.US_ASCII.name();
80  
81      /**
82       * Sixteen-bit Unicode Transformation Format, The byte order specified by a mandatory initial byte-order mark
83       * (either order accepted on input, big-endian used on output)
84       * <p>
85       * Every implementation of the Java platform is required to support this character encoding.
86       * </p>
87       *
88       * @see Charset
89       */
90      public static final String UTF_16 = StandardCharsets.UTF_16.name();
91  
92      /**
93       * Sixteen-bit Unicode Transformation Format, big-endian byte order.
94       * <p>
95       * Every implementation of the Java platform is required to support this character encoding.
96       * </p>
97       *
98       * @see Charset
99       */
100     public static final String UTF_16BE = StandardCharsets.UTF_16BE.name();
101 
102     /**
103      * Sixteen-bit Unicode Transformation Format, little-endian byte order.
104      * <p>
105      * Every implementation of the Java platform is required to support this character encoding.
106      * </p>
107      *
108      * @see Charset
109      */
110     public static final String UTF_16LE = StandardCharsets.UTF_16LE.name();
111 
112     /**
113      * Eight-bit Unicode Transformation Format.
114      * <p>
115      * Every implementation of the Java platform is required to support this character encoding.
116      * </p>
117      *
118      * @see Charset
119      */
120     public static final String UTF_8 = StandardCharsets.UTF_8.name();
121 
122     /**
123      * TODO Make private in 2.0.
124      *
125      * @deprecated TODO Make private in 2.0.
126      */
127     @Deprecated
128     public CharEncoding() {
129         // empty
130     }
131 
132 }