001/*
002 * Copyright (C) 2007 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005 * in compliance with the License. You may obtain a copy of the License at
006 *
007 * http://www.apache.org/licenses/LICENSE-2.0
008 *
009 * Unless required by applicable law or agreed to in writing, software distributed under the License
010 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
011 * or implied. See the License for the specific language governing permissions and limitations under
012 * the License.
013 */
014
015package com.google.common.base;
016
017import com.google.common.annotations.GwtCompatible;
018import com.google.common.annotations.GwtIncompatible;
019import com.google.common.annotations.J2ktIncompatible;
020import java.nio.charset.Charset;
021
022/**
023 * Contains constant definitions for the six standard {@link Charset} instances, which are
024 * guaranteed to be supported by all Java platform implementations.
025 *
026 * <p>Assuming you're free to choose, note that <b>{@link #UTF_8} is widely preferred</b>.
027 *
028 * <p>See the Guava User Guide article on <a
029 * href="https://github.com/google/guava/wiki/StringsExplained#charsets">{@code Charsets}</a>.
030 *
031 * @author Mike Bostock
032 * @since 1.0
033 */
034@GwtCompatible(emulated = true)
035@ElementTypesAreNonnullByDefault
036public final class Charsets {
037  private Charsets() {}
038
039  /**
040   * US-ASCII: seven-bit ASCII, the Basic Latin block of the Unicode character set (ISO646-US).
041   *
042   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
043   * java.nio.charset.StandardCharsets#US_ASCII} instead.
044   *
045   */
046  @J2ktIncompatible
047  @GwtIncompatible // Charset not supported by GWT
048  public static final Charset US_ASCII = Charset.forName("US-ASCII");
049
050  /**
051   * ISO-8859-1: ISO Latin Alphabet Number 1 (ISO-LATIN-1).
052   *
053   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
054   * java.nio.charset.StandardCharsets#ISO_8859_1} instead.
055   *
056   */
057  public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
058
059  /**
060   * UTF-8: eight-bit UCS Transformation Format.
061   *
062   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
063   * java.nio.charset.StandardCharsets#UTF_8} instead.
064   *
065   */
066  public static final Charset UTF_8 = Charset.forName("UTF-8");
067
068  /**
069   * UTF-16BE: sixteen-bit UCS Transformation Format, big-endian byte order.
070   *
071   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
072   * java.nio.charset.StandardCharsets#UTF_16BE} instead.
073   *
074   */
075  @J2ktIncompatible
076  @GwtIncompatible // Charset not supported by GWT
077  public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
078
079  /**
080   * UTF-16LE: sixteen-bit UCS Transformation Format, little-endian byte order.
081   *
082   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
083   * java.nio.charset.StandardCharsets#UTF_16LE} instead.
084   *
085   */
086  @J2ktIncompatible
087  @GwtIncompatible // Charset not supported by GWT
088  public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
089
090  /**
091   * UTF-16: sixteen-bit UCS Transformation Format, byte order identified by an optional byte-order
092   * mark.
093   *
094   * <p><b>Java 7+ users:</b> this constant should be treated as deprecated; use {@link
095   * java.nio.charset.StandardCharsets#UTF_16} instead.
096   *
097   */
098  @J2ktIncompatible
099  @GwtIncompatible // Charset not supported by GWT
100  public static final Charset UTF_16 = Charset.forName("UTF-16");
101
102  /*
103   * Please do not add new Charset references to this class, unless those character encodings are
104   * part of the set required to be supported by all Java platform implementations! Any Charsets
105   * initialized here may cause unexpected delays when this class is loaded. See the Charset
106   * Javadocs for the list of built-in character encodings.
107   */
108}