    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    }