/*
 * 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.lang;

import java.io.UnsupportedEncodingException;

/**
 * <p>
 * Character encoding names required of every implementation of the Java platform.
 * </p>
 * 
 * <p>
 * According to <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
 * encoding names</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.</cite>
 * </p>
 * </p>
 * 
 * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character encoding
 *      names</a>
 * @author Apache Software Foundation
 * @since 2.1
 * @version $Id$
 */
public class CharEncoding {

    /**
     * <p>
     * ISO Latin Alphabet #1, also known as ISO-LATIN-1.
     * </p>
     * <p>
     * Every implementation of the Java platform is required to support this character encoding.
     * </p>
     * 
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
     *      encoding names</a>
     */
    public static final String ISO_8859_1 = "ISO-8859-1";

    /**
     * <p>
     * Seven-bit ASCII, also known as ISO646-US, also known as the Basic Latin block of the Unicode character set.
     * </p>
     * <p>
     * Every implementation of the Java platform is required to support this character encoding.
     * </p>
     * 
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
     *      encoding names</a>
     */
    public static final String US_ASCII = "US-ASCII";

    /**
     * <p>
     * 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).
     * </p>
     * <p>
     * Every implementation of the Java platform is required to support this character encoding.
     * </p>
     * 
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
     *      encoding names</a>
     */
    public static final String UTF_16 = "UTF-16";

    /**
     * <p>
     * Sixteen-bit Unicode Transformation Format, big-endian byte order.
     * </p>
     * <p>
     * Every implementation of the Java platform is required to support this character encoding.
     * </p>
     * 
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
     *      encoding names</a>
     */
    public static final String UTF_16BE = "UTF-16BE";

    /**
     * <p>
     * Sixteen-bit Unicode Transformation Format, little-endian byte order.
     * </p>
     * <p>
     * Every implementation of the Java platform is required to support this character encoding.
     * </p>
     * 
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
     *      encoding names</a>
     */
    public static final String UTF_16LE = "UTF-16LE";

    /**
     * <p>
     * Eight-bit Unicode Transformation Format.
     * </p>
     * <p>
     * Every implementation of the Java platform is required to support this character encoding.
     * </p>
     * 
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
     *      encoding names</a>
     */
    public static final String UTF_8 = "UTF-8";

    /**
     * <p>
     * Returns whether the named charset is supported.
     * </p>
     * <p>
     * This is similar to <a
     * href="http://java.sun.com/j2se/1.4.2/docs/api/java/nio/charset/Charset.html#isSupported(java.lang.String)">
     * java.nio.charset.Charset.isSupported(String)</a>
     * </p>
     * 
     * @param name
     *            the name of the requested charset; may be either a canonical name or an alias
     * @return <code>true</code> if, and only if, support for the named charset is available in the current Java
     *         virtual machine
     * 
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/package-summary.html#charenc">JRE character
     *      encoding names</a>
     */
    public static boolean isSupported(String name) {
        if (name == null) {
            return false;
        }
        try {
            new String(ArrayUtils.EMPTY_BYTE_ARRAY, name);
        } catch (UnsupportedEncodingException e) {
            return false;
        }
        return true;
    }

}