001 /*
002 * Copyright (C) 2007 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017 package com.google.common.base;
018
019 import com.google.common.annotations.GwtCompatible;
020 import com.google.common.annotations.GwtIncompatible;
021
022 import java.nio.charset.Charset;
023
024 /**
025 * Contains constant definitions for the six standard {@link Charset} instances, which are
026 * guaranteed to be supported by all Java platform implementations.
027 *
028 * <p>Assuming you're free to choose, note that <b>{@link #UTF_8} is widely preferred</b>.
029 *
030 * <p>See the Guava User Guide article on <a
031 * href="http://code.google.com/p/guava-libraries/wiki/StringsExplained#Charsets">
032 * {@code Charsets}</a>.
033 *
034 * @author Mike Bostock
035 * @since 1.0
036 */
037 @GwtCompatible(emulated = true)
038 public final class Charsets {
039 private Charsets() {}
040
041 /**
042 * US-ASCII: seven-bit ASCII, the Basic Latin block of the Unicode character set (ISO646-US).
043 */
044 @GwtIncompatible("Non-UTF-8 Charset")
045 public static final Charset US_ASCII = Charset.forName("US-ASCII");
046
047 /**
048 * ISO-8859-1: ISO Latin Alphabet Number 1 (ISO-LATIN-1).
049 */
050 @GwtIncompatible("Non-UTF-8 Charset")
051 public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
052
053 /**
054 * UTF-8: eight-bit UCS Transformation Format.
055 */
056 public static final Charset UTF_8 = Charset.forName("UTF-8");
057
058 /**
059 * UTF-16BE: sixteen-bit UCS Transformation Format, big-endian byte order.
060 */
061 @GwtIncompatible("Non-UTF-8 Charset")
062 public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
063
064 /**
065 * UTF-16LE: sixteen-bit UCS Transformation Format, little-endian byte order.
066 */
067 @GwtIncompatible("Non-UTF-8 Charset")
068 public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
069
070 /**
071 * UTF-16: sixteen-bit UCS Transformation Format, byte order identified by an optional byte-order
072 * mark.
073 */
074 @GwtIncompatible("Non-UTF-8 Charset")
075 public static final Charset UTF_16 = Charset.forName("UTF-16");
076
077 /*
078 * Please do not add new Charset references to this class, unless those character encodings are
079 * part of the set required to be supported by all Java platform implementations! Any Charsets
080 * initialized here may cause unexpected delays when this class is loaded. See the Charset
081 * Javadocs for the list of built-in character encodings.
082 */
083 }