001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *   http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.compress.utils;
019
020import java.nio.charset.Charset;
021import java.nio.charset.StandardCharsets;
022
023/**
024 * Charsets required of every implementation of the Java platform.
025 *
026 * From the Java documentation <a href="https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html">Standard charsets</a>:
027 * <p>
028 * <cite>Every implementation of the Java platform is required to support the following character encodings. Consult the release documentation for your
029 * implementation to see if any other encodings are supported. Consult the release documentation for your implementation to see if any other encodings are
030 * supported. </cite>
031 * </p>
032 *
033 * <dl>
034 * <dt>{@code US-ASCII}</dt>
035 * <dd>Seven-bit ASCII, a.k.a. ISO646-US, a.k.a. the Basic Latin block of the Unicode character set.</dd>
036 * <dt>{@code ISO-8859-1}</dt>
037 * <dd>ISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1.</dd>
038 * <dt>{@code UTF-8}</dt>
039 * <dd>Eight-bit Unicode Transformation Format.</dd>
040 * <dt>{@code UTF-16BE}</dt>
041 * <dd>Sixteen-bit Unicode Transformation Format, big-endian byte order.</dd>
042 * <dt>{@code UTF-16LE}</dt>
043 * <dd>Sixteen-bit Unicode Transformation Format, little-endian byte order.</dd>
044 * <dt>{@code UTF-16}</dt>
045 * <dd>Sixteen-bit Unicode Transformation Format, byte order specified by a mandatory initial byte-order mark (either order accepted on input, big-endian used
046 * on output.)</dd>
047 * </dl>
048 *
049 * <p>
050 * This class best belongs in the Commons Lang or IO project. Even if a similar class is defined in another Commons component, it is not foreseen that Commons
051 * Compress would be made to depend on another Commons component.
052 * </p>
053 *
054 * @see <a href="https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
055 * @see StandardCharsets
056 * @since 1.4
057 * @deprecated Use {@link org.apache.commons.io.Charsets}.
058 */
059@Deprecated
060public class Charsets {
061
062    //
063    // This class should only contain Charset instances for required encodings. This guarantees that it will load correctly and
064    // without delay on all Java platforms.
065    //
066
067    /**
068     * CharsetNamesISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1.
069     * <p>
070     * Every implementation of the Java platform is required to support this character encoding.
071     * </p>
072     *
073     * @see <a href="https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
074     * @deprecated replaced by {@link StandardCharsets} in Java 7
075     */
076    @Deprecated
077    public static final Charset ISO_8859_1 = StandardCharsets.ISO_8859_1;
078
079    /**
080     * <p>
081     * Seven-bit ASCII, also known as ISO646-US, also known as the Basic Latin block of the Unicode character set.
082     * </p>
083     * <p>
084     * Every implementation of the Java platform is required to support this character encoding.
085     * </p>
086     *
087     * @see <a href="https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
088     * @deprecated replaced by {@link StandardCharsets} in Java 7
089     */
090    @Deprecated
091    public static final Charset US_ASCII = StandardCharsets.US_ASCII;
092
093    /**
094     * <p>
095     * Sixteen-bit Unicode Transformation Format, The byte order specified by a mandatory initial byte-order mark (either order accepted on input, big-endian
096     * used on output)
097     * </p>
098     * <p>
099     * Every implementation of the Java platform is required to support this character encoding.
100     * </p>
101     *
102     * @see <a href="https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
103     * @deprecated replaced by {@link StandardCharsets} in Java 7
104     */
105    @Deprecated
106    public static final Charset UTF_16 = StandardCharsets.UTF_16;
107
108    /**
109     * <p>
110     * Sixteen-bit Unicode Transformation Format, big-endian byte order.
111     * </p>
112     * <p>
113     * Every implementation of the Java platform is required to support this character encoding.
114     * </p>
115     *
116     * @see <a href="https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
117     * @deprecated replaced by {@link StandardCharsets} in Java 7
118     */
119    @Deprecated
120    public static final Charset UTF_16BE = StandardCharsets.UTF_16BE;
121
122    /**
123     * <p>
124     * Sixteen-bit Unicode Transformation Format, little-endian byte order.
125     * </p>
126     * <p>
127     * Every implementation of the Java platform is required to support this character encoding.
128     * </p>
129     *
130     * @see <a href="https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
131     * @deprecated replaced by {@link StandardCharsets} in Java 7
132     */
133    @Deprecated
134    public static final Charset UTF_16LE = StandardCharsets.UTF_16LE;
135
136    /**
137     * <p>
138     * Eight-bit Unicode Transformation Format.
139     * </p>
140     * <p>
141     * Every implementation of the Java platform is required to support this character encoding.
142     * </p>
143     *
144     * @see <a href="https://docs.oracle.com/javase/8/docs/api/java/nio/charset/Charset.html">Standard charsets</a>
145     * @deprecated replaced by {@link StandardCharsets} in Java 7
146     */
147    @Deprecated
148    public static final Charset UTF_8 = StandardCharsets.UTF_8;
149
150    /**
151     * Returns the given Charset or the default Charset if the given Charset is null.
152     *
153     * @param charset A charset or null.
154     * @return the given Charset or the default Charset if the given Charset is null
155     */
156    public static Charset toCharset(final Charset charset) {
157        return charset == null ? Charset.defaultCharset() : charset;
158    }
159
160    /**
161     * Returns a Charset for the named charset. If the name is null, return the default Charset.
162     *
163     * @param charset The name of the requested charset, may be null.
164     * @return a Charset for the named charset
165     * @throws java.nio.charset.UnsupportedCharsetException If the named charset is unavailable
166     * @throws java.nio.charset.IllegalCharsetNameException If the given charset name is illegal
167     */
168    public static Charset toCharset(final String charset) {
169        return charset == null ? Charset.defaultCharset() : Charset.forName(charset);
170    }
171}