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 java.nio.charset.Charset;
020
021/**
022 * Contains constant definitions for the six standard {@link Charset} instances, which are
023 * guaranteed to be supported by all Java platform implementations.
024 *
025 * <p>Assuming you're free to choose, note that <b>{@link #UTF_8} is widely preferred</b>.
026 *
027 * <p>See the Guava User Guide article on <a
028 * href="https://github.com/google/guava/wiki/StringsExplained#charsets">{@code Charsets}</a>.
029 *
030 * @author Mike Bostock
031 * @since 1.0
032 */
033@GwtCompatible(emulated = true)
034public final class Charsets {
035  private Charsets() {}
036
037  /**
038   * US-ASCII: seven-bit ASCII, the Basic Latin block of the Unicode character set (ISO646-US).
039   *
040   * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
041   * java.nio.charset.StandardCharsets#US_ASCII} instead.
042   *
043   */
044  @GwtIncompatible // Charset not supported by GWT
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   * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
051   * java.nio.charset.StandardCharsets#ISO_8859_1} instead.
052   *
053   */
054  public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
055
056  /**
057   * UTF-8: eight-bit UCS Transformation Format.
058   *
059   * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
060   * java.nio.charset.StandardCharsets#UTF_8} instead.
061   *
062   */
063  public static final Charset UTF_8 = Charset.forName("UTF-8");
064
065  /**
066   * UTF-16BE: sixteen-bit UCS Transformation Format, big-endian byte order.
067   *
068   * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
069   * java.nio.charset.StandardCharsets#UTF_16BE} instead.
070   *
071   */
072  @GwtIncompatible // Charset not supported by GWT
073  public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
074
075  /**
076   * UTF-16LE: sixteen-bit UCS Transformation Format, little-endian byte order.
077   *
078   * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
079   * java.nio.charset.StandardCharsets#UTF_16LE} instead.
080   *
081   */
082  @GwtIncompatible // Charset not supported by GWT
083  public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
084
085  /**
086   * UTF-16: sixteen-bit UCS Transformation Format, byte order identified by an optional byte-order
087   * mark.
088   *
089   * <p><b>Note for Java 7 and later:</b> this constant should be treated as deprecated; use {@link
090   * java.nio.charset.StandardCharsets#UTF_16} instead.
091   *
092   */
093  @GwtIncompatible // Charset not supported by GWT
094  public static final Charset UTF_16 = Charset.forName("UTF-16");
095
096  /*
097   * Please do not add new Charset references to this class, unless those character encodings are
098   * part of the set required to be supported by all Java platform implementations! Any Charsets
099   * initialized here may cause unexpected delays when this class is loaded. See the Charset
100   * Javadocs for the list of built-in character encodings.
101   */
102}