Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.codec; import java.nio.charset.Charset; /** * Charsets required of every implementation of the Java platform. * * From the Java documentation <a href="http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard * charsets</a>: * <p> * <cite>Every implementation of the Java platform is required to support the following character encodings. Consult the * release documentation for your implementation to see if any other encodings are supported. Consult the release * documentation for your implementation to see if any other encodings are supported. </cite> * </p> * * <ul> * <li><code>US-ASCII</code><br/> * Seven-bit ASCII, a.k.a. ISO646-US, a.k.a. the Basic Latin block of the Unicode character set.</li> * <li><code>ISO-8859-1</code><br/> * ISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1.</li> * <li><code>UTF-8</code><br/> * Eight-bit Unicode Transformation Format.</li> * <li><code>UTF-16BE</code><br/> * Sixteen-bit Unicode Transformation Format, big-endian byte order.</li> * <li><code>UTF-16LE</code><br/> * Sixteen-bit Unicode Transformation Format, little-endian byte order.</li> * <li><code>UTF-16</code><br/> * Sixteen-bit Unicode Transformation Format, byte order specified by a mandatory initial byte-order mark (either order * accepted on input, big-endian used on output.)</li> * </ul> * * This perhaps would best belong in the Commons Lang project. Even if a similar class is defined in Commons Lang, it is * not foreseen that Commons Codec would be made to depend on Commons Lang. * * <p> * This class is immutable and thread-safe. * </p> * * @see <a href="http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> * @since 1.7 * @version $Id: CharEncoding.java 1173287 2011-09-20 18:16:19Z ggregory $ */ public class Charsets { // // This class should only contain Charset instances for required encodings. This guarantees that it will load // correctly and without delay on all Java platforms. // /** * Returns the given Charset or the default Charset if the given Charset is null. * * @param charset * A charset or null. * @return the given Charset or the default Charset if the given Charset is null */ public static Charset toCharset(final Charset charset) { return charset == null ? Charset.defaultCharset() : charset; } /** * Returns a Charset for the named charset. If the name is null, return the default Charset. * * @param charset * The name of the requested charset, may be null. * @return a Charset for the named charset * @throws java.nio.charset.UnsupportedCharsetException * If the named charset is unavailable */ public static Charset toCharset(final String charset) { return charset == null ? Charset.defaultCharset() : Charset.forName(charset); } /** * CharEncodingISO Latin Alphabet No. 1, a.k.a. ISO-LATIN-1. * <p> * Every implementation of the Java platform is required to support this character encoding. * * @see <a href="http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> */ public static final Charset ISO_8859_1 = Charset.forName(CharEncoding.ISO_8859_1); /** * Seven-bit ASCII, also known as ISO646-US, also known as the Basic Latin block of the Unicode character set. * <p> * Every implementation of the Java platform is required to support this character encoding. * * @see <a href="http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> */ public static final Charset US_ASCII = Charset.forName(CharEncoding.US_ASCII); /** * Sixteen-bit Unicode Transformation Format, The byte order specified by a mandatory initial byte-order mark * (either order accepted on input, big-endian used on output) * <p> * Every implementation of the Java platform is required to support this character encoding. * * @see <a href="http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> */ public static final Charset UTF_16 = Charset.forName(CharEncoding.UTF_16); /** * Sixteen-bit Unicode Transformation Format, big-endian byte order. * <p> * Every implementation of the Java platform is required to support this character encoding. * * @see <a href="http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> */ public static final Charset UTF_16BE = Charset.forName(CharEncoding.UTF_16BE); /** * Sixteen-bit Unicode Transformation Format, little-endian byte order. * <p> * Every implementation of the Java platform is required to support this character encoding. * * @see <a href="http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> */ public static final Charset UTF_16LE = Charset.forName(CharEncoding.UTF_16LE); /** * Eight-bit Unicode Transformation Format. * <p> * Every implementation of the Java platform is required to support this character encoding. * * @see <a href="http://docs.oracle.com/javase/6/docs/api/java/nio/charset/Charset.html">Standard charsets</a> */ public static final Charset UTF_8 = Charset.forName(CharEncoding.UTF_8); }