1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 package org.apache.commons.compress.utils; 20 21 import java.nio.charset.Charset; 22 import java.nio.charset.StandardCharsets; 23 24 /** 25 * Charsets required of every implementation of the Java platform. 26 * 27 * From the Java documentation <a href="https://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard 28 * charsets</a>: 29 * <p> 30 * <cite>Every implementation of the Java platform is required to support the following character encodings. Consult the 31 * release documentation for your implementation to see if any other encodings are supported. Consult the release 32 * documentation for your implementation to see if any other encodings are supported. </cite> 33 * </p> 34 * 35 * <dl> 36 * <dt><code>US-ASCII</code></dt> 37 * <dd>Seven-bit ASCII, a.k.a. ISO646-US, a.k.a. the Basic Latin block of the Unicode character set.</dd> 38 * <dt><code>ISO-8859-1</code></dt> 39 * <dd>ISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1.</dd> 40 * <dt><code>UTF-8</code></dt> 41 * <dd>Eight-bit Unicode Transformation Format.</dd> 42 * <dt><code>UTF-16BE</code></dt> 43 * <dd>Sixteen-bit Unicode Transformation Format, big-endian byte order.</dd> 44 * <dt><code>UTF-16LE</code></dt> 45 * <dd>Sixteen-bit Unicode Transformation Format, little-endian byte order.</dd> 46 * <dt><code>UTF-16</code></dt> 47 * <dd>Sixteen-bit Unicode Transformation Format, byte order specified by a mandatory initial byte-order mark (either order 48 * accepted on input, big-endian used on output.)</dd> 49 * </dl> 50 * 51 * <p>This class best belongs in the Commons Lang or IO project. Even if a similar class is defined in another Commons 52 * component, it is not foreseen that Commons Compress would be made to depend on another Commons component.</p> 53 * 54 * @see <a href="https://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> 55 * @see StandardCharsets 56 * @since 1.4 57 */ 58 public class Charsets { 59 60 // 61 // This class should only contain Charset instances for required encodings. This guarantees that it will load correctly and 62 // without delay on all Java platforms. 63 // 64 65 /** 66 * Returns the given Charset or the default Charset if the given Charset is null. 67 * 68 * @param charset 69 * A charset or null. 70 * @return the given Charset or the default Charset if the given Charset is null 71 */ 72 public static Charset toCharset(final Charset charset) { 73 return charset == null ? Charset.defaultCharset() : charset; 74 } 75 76 /** 77 * Returns a Charset for the named charset. If the name is null, return the default Charset. 78 * 79 * @param charset 80 * The name of the requested charset, may be null. 81 * @return a Charset for the named charset 82 * @throws java.nio.charset.UnsupportedCharsetException 83 * If the named charset is unavailable 84 * @throws java.nio.charset.IllegalCharsetNameException 85 * If the given charset name is illegal 86 */ 87 public static Charset toCharset(final String charset) { 88 return charset == null ? Charset.defaultCharset() : Charset.forName(charset); 89 } 90 91 /** 92 * CharsetNamesISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1. 93 * <p> 94 * Every implementation of the Java platform is required to support this character encoding. 95 * </p> 96 * 97 * @see <a href="https://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> 98 * @deprecated replaced by {@link StandardCharsets} in Java 7 99 */ 100 public static final Charset ISO_8859_1 = StandardCharsets.ISO_8859_1; 101 102 /** 103 * <p> 104 * Seven-bit ASCII, also known as ISO646-US, also known as the Basic Latin block of the Unicode character set. 105 * </p> 106 * <p> 107 * Every implementation of the Java platform is required to support this character encoding. 108 * </p> 109 * 110 * @see <a href="https://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> 111 * @deprecated replaced by {@link StandardCharsets} in Java 7 112 */ 113 public static final Charset US_ASCII = StandardCharsets.US_ASCII; 114 115 /** 116 * <p> 117 * Sixteen-bit Unicode Transformation Format, The byte order specified by a mandatory initial byte-order mark 118 * (either order accepted on input, big-endian used on output) 119 * </p> 120 * <p> 121 * Every implementation of the Java platform is required to support this character encoding. 122 * </p> 123 * 124 * @see <a href="https://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> 125 * @deprecated replaced by {@link StandardCharsets} in Java 7 126 */ 127 public static final Charset UTF_16 = StandardCharsets.UTF_16; 128 129 /** 130 * <p> 131 * Sixteen-bit Unicode Transformation Format, big-endian byte order. 132 * </p> 133 * <p> 134 * Every implementation of the Java platform is required to support this character encoding. 135 * </p> 136 * 137 * @see <a href="https://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> 138 * @deprecated replaced by {@link StandardCharsets} in Java 7 139 */ 140 public static final Charset UTF_16BE = StandardCharsets.UTF_16BE; 141 142 /** 143 * <p> 144 * Sixteen-bit Unicode Transformation Format, little-endian byte order. 145 * </p> 146 * <p> 147 * Every implementation of the Java platform is required to support this character encoding. 148 * </p> 149 * 150 * @see <a href="https://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> 151 * @deprecated replaced by {@link StandardCharsets} in Java 7 152 */ 153 public static final Charset UTF_16LE = StandardCharsets.UTF_16LE; 154 155 /** 156 * <p> 157 * Eight-bit Unicode Transformation Format. 158 * </p> 159 * <p> 160 * Every implementation of the Java platform is required to support this character encoding. 161 * </p> 162 * 163 * @see <a href="https://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> 164 * @deprecated replaced by {@link StandardCharsets} in Java 7 165 */ 166 public static final Charset UTF_8 = StandardCharsets.UTF_8; 167 } 168
