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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.lang;
19  
20  import java.io.UnsupportedEncodingException;
21  
22  /**
23   * <p>
24   * Character encoding names required of every implementation of the Java platform.
25   * </p>
26   * 
27   * <p>
28   * According to <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
29   * encoding names</a>:
30   * <p>
31   * <cite>Every implementation of the Java platform is required to support the following character encodings. Consult the
32   * release documentation for your implementation to see if any other encodings are supported.</cite>
33   * </p>
34   * </p>
35   * 
36   * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character encoding
37   *      names</a>
38   * @author Apache Software Foundation
39   * @since 2.1
40   * @version $Id: CharEncoding.java 437554 2006-08-28 06:21:41Z bayard $
41   */
42  public class CharEncoding {
43  
44      /**
45       * <p>
46       * ISO Latin Alphabet #1, also known as ISO-LATIN-1.
47       * </p>
48       * <p>
49       * Every implementation of the Java platform is required to support this character encoding.
50       * </p>
51       * 
52       * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
53       *      encoding names</a>
54       */
55      public static final String ISO_8859_1 = "ISO-8859-1";
56  
57      /**
58       * <p>
59       * Seven-bit ASCII, also known as ISO646-US, also known as the Basic Latin block of the Unicode character set.
60       * </p>
61       * <p>
62       * Every implementation of the Java platform is required to support this character encoding.
63       * </p>
64       * 
65       * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
66       *      encoding names</a>
67       */
68      public static final String US_ASCII = "US-ASCII";
69  
70      /**
71       * <p>
72       * Sixteen-bit Unicode Transformation Format, byte order specified by a mandatory initial byte-order mark (either
73       * order accepted on input, big-endian used on output).
74       * </p>
75       * <p>
76       * Every implementation of the Java platform is required to support this character encoding.
77       * </p>
78       * 
79       * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
80       *      encoding names</a>
81       */
82      public static final String UTF_16 = "UTF-16";
83  
84      /**
85       * <p>
86       * Sixteen-bit Unicode Transformation Format, big-endian byte order.
87       * </p>
88       * <p>
89       * Every implementation of the Java platform is required to support this character encoding.
90       * </p>
91       * 
92       * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
93       *      encoding names</a>
94       */
95      public static final String UTF_16BE = "UTF-16BE";
96  
97      /**
98       * <p>
99       * Sixteen-bit Unicode Transformation Format, little-endian byte order.
100      * </p>
101      * <p>
102      * Every implementation of the Java platform is required to support this character encoding.
103      * </p>
104      * 
105      * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
106      *      encoding names</a>
107      */
108     public static final String UTF_16LE = "UTF-16LE";
109 
110     /**
111      * <p>
112      * Eight-bit Unicode Transformation Format.
113      * </p>
114      * <p>
115      * Every implementation of the Java platform is required to support this character encoding.
116      * </p>
117      * 
118      * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
119      *      encoding names</a>
120      */
121     public static final String UTF_8 = "UTF-8";
122 
123     /**
124      * <p>
125      * Returns whether the named charset is supported.
126      * </p>
127      * <p>
128      * This is similar to <a
129      * href="http://java.sun.com/j2se/1.4.2/docs/api/java/nio/charset/Charset.html#isSupported(java.lang.String)">
130      * java.nio.charset.Charset.isSupported(String)</a>
131      * </p>
132      * 
133      * @param name
134      *            the name of the requested charset; may be either a canonical name or an alias
135      * @return <code>true</code> if, and only if, support for the named charset is available in the current Java
136      *         virtual machine
137      * 
138      * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
139      *      encoding names</a>
140      */
141     public static boolean isSupported(String name) {
142         if (name == null) {
143             return false;
144         }
145         try {
146             new String(ArrayUtils.EMPTY_BYTE_ARRAY, name);
147         } catch (UnsupportedEncodingException e) {
148             return false;
149         }
150         return true;
151     }
152 
153 }