    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
    018    package org.apache.commons.lang;
    019
    020    import java.io.UnsupportedEncodingException;
    021
    022    /**
    023     * <p>
    024     * Character encoding names required of every implementation of the Java platform.
    025     * </p>
    026     *
    027     * <p>
    028     * According to <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
    029     * encoding names</a>:
    030     * <p>
    031     * <cite>Every implementation of the Java platform is required to support the following character encodings. Consult the
    032     * release documentation for your implementation to see if any other encodings are supported.</cite>
    033     * </p>
    034     * </p>
    035     *
    036     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character encoding
    037     *      names</a>
    038     * @author Apache Software Foundation
    039     * @since 2.1
    040     * @version $Id: CharEncoding.java 437554 2006-08-28 06:21:41Z bayard $
    041     */
    042    public class CharEncoding {
    043
    044        /**
    045         * <p>
    046         * ISO Latin Alphabet #1, also known as ISO-LATIN-1.
    047         * </p>
    048         * <p>
    049         * Every implementation of the Java platform is required to support this character encoding.
    050         * </p>
    051         *
    052         * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
    053         *      encoding names</a>
    054         */
    055        public static final String ISO_8859_1 = "ISO-8859-1";
    056
    057        /**
    058         * <p>
    059         * Seven-bit ASCII, also known as ISO646-US, also known as the Basic Latin block of the Unicode character set.
    060         * </p>
    061         * <p>
    062         * Every implementation of the Java platform is required to support this character encoding.
    063         * </p>
    064         *
    065         * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
    066         *      encoding names</a>
    067         */
    068        public static final String US_ASCII = "US-ASCII";
    069
    070        /**
    071         * <p>
    072         * Sixteen-bit Unicode Transformation Format, byte order specified by a mandatory initial byte-order mark (either
    073         * order accepted on input, big-endian used on output).
    074         * </p>
    075         * <p>
    076         * Every implementation of the Java platform is required to support this character encoding.
    077         * </p>
    078         *
    079         * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
    080         *      encoding names</a>
    081         */
    082        public static final String UTF_16 = "UTF-16";
    083
    084        /**
    085         * <p>
    086         * Sixteen-bit Unicode Transformation Format, big-endian byte order.
    087         * </p>
    088         * <p>
    089         * Every implementation of the Java platform is required to support this character encoding.
    090         * </p>
    091         *
    092         * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
    093         *      encoding names</a>
    094         */
    095        public static final String UTF_16BE = "UTF-16BE";
    096
    097        /**
    098         * <p>
    099         * Sixteen-bit Unicode Transformation Format, little-endian byte order.
    100         * </p>
    101         * <p>
    102         * Every implementation of the Java platform is required to support this character encoding.
    103         * </p>
    104         *
    105         * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
    106         *      encoding names</a>
    107         */
    108        public static final String UTF_16LE = "UTF-16LE";
    109
    110        /**
    111         * <p>
    112         * Eight-bit Unicode Transformation Format.
    113         * </p>
    114         * <p>
    115         * Every implementation of the Java platform is required to support this character encoding.
    116         * </p>
    117         *
    118         * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
    119         *      encoding names</a>
    120         */
    121        public static final String UTF_8 = "UTF-8";
    122
    123        /**
    124         * <p>
    125         * Returns whether the named charset is supported.
    126         * </p>
    127         * <p>
    128         * This is similar to <a
    129         * href="http://java.sun.com/j2se/1.4.2/docs/api/java/nio/charset/Charset.html#isSupported(java.lang.String)">
    130         * java.nio.charset.Charset.isSupported(String)</a>
    131         * </p>
    132         *
    133         * @param name
    134         *            the name of the requested charset; may be either a canonical name or an alias
    135         * @return <code>true</code> if, and only if, support for the named charset is available in the current Java
    136         *         virtual machine
    137         *
    138         * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
    139         *      encoding names</a>
    140         */
    141        public static boolean isSupported(String name) {
    142            if (name == null) {
    143                return false;
    144            }
    145            try {
    146                new String(ArrayUtils.EMPTY_BYTE_ARRAY, name);
    147            } catch (UnsupportedEncodingException e) {
    148                return false;
    149            }
    150            return true;
    151        }
    152
    153    }