1 /*
2 * Copyright (C) 2007 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14
15 package com.google.common.base;
16
17 import com.google.common.annotations.GwtCompatible;
18 import com.google.common.annotations.GwtIncompatible;
19 import java.nio.charset.Charset;
20
21 /**
22 * Contains constant definitions for the six standard {@link Charset} instances, which are
23 * guaranteed to be supported by all Java platform implementations.
24 *
25 * <p>Assuming you're free to choose, note that <b>{@link #UTF_8} is widely preferred</b>.
26 *
27 * <p>See the Guava User Guide article on <a
28 * href="https://github.com/google/guava/wiki/StringsExplained#charsets">{@code Charsets}</a>.
29 *
30 * @author Mike Bostock
31 * @since 1.0
32 */
33 @GwtCompatible(emulated = true)
34 @ElementTypesAreNonnullByDefault
35 public final class Charsets {
36 private Charsets() {}
37
38 /**
39 * US-ASCII: seven-bit ASCII, the Basic Latin block of the Unicode character set (ISO646-US).
40 *
41 * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
42 * java.nio.charset.StandardCharsets#US_ASCII} instead.
43 *
44 */
45 @GwtIncompatible // Charset not supported by GWT
46 public static final Charset US_ASCII = Charset.forName("US-ASCII");
47
48 /**
49 * ISO-8859-1: ISO Latin Alphabet Number 1 (ISO-LATIN-1).
50 *
51 * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
52 * java.nio.charset.StandardCharsets#ISO_8859_1} instead.
53 *
54 */
55 public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
56
57 /**
58 * UTF-8: eight-bit UCS Transformation Format.
59 *
60 * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
61 * java.nio.charset.StandardCharsets#UTF_8} instead.
62 *
63 */
64 public static final Charset UTF_8 = Charset.forName("UTF-8");
65
66 /**
67 * UTF-16BE: sixteen-bit UCS Transformation Format, big-endian byte order.
68 *
69 * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
70 * java.nio.charset.StandardCharsets#UTF_16BE} instead.
71 *
72 */
73 @GwtIncompatible // Charset not supported by GWT
74 public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
75
76 /**
77 * UTF-16LE: sixteen-bit UCS Transformation Format, little-endian byte order.
78 *
79 * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
80 * java.nio.charset.StandardCharsets#UTF_16LE} instead.
81 *
82 */
83 @GwtIncompatible // Charset not supported by GWT
84 public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
85
86 /**
87 * UTF-16: sixteen-bit UCS Transformation Format, byte order identified by an optional byte-order
88 * mark.
89 *
90 * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
91 * java.nio.charset.StandardCharsets#UTF_16} instead.
92 *
93 */
94 @GwtIncompatible // Charset not supported by GWT
95 public static final Charset UTF_16 = Charset.forName("UTF-16");
96
97 /*
98 * Please do not add new Charset references to this class, unless those character encodings are
99 * part of the set required to be supported by all Java platform implementations! Any Charsets
100 * initialized here may cause unexpected delays when this class is loaded. See the Charset
101 * Javadocs for the list of built-in character encodings.
102 */
103 }