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.codec.net;
019
020import org.apache.commons.codec.DecoderException;
021
022/**
023 * Utility methods for this package.
024 *
025 * <p>This class is immutable and thread-safe.</p>
026 *
027 * @version $Id: Utils.java 1458495 2013-03-19 20:19:13Z sebb $
028 * @since 1.4
029 */
030class Utils {
031
032    /**
033     * Returns the numeric value of the character <code>b</code> in radix 16.
034     *
035     * @param b
036     *            The byte to be converted.
037     * @return The numeric value represented by the character in radix 16.
038     *
039     * @throws DecoderException
040     *             Thrown when the byte is not valid per {@link Character#digit(char,int)}
041     */
042    static int digit16(final byte b) throws DecoderException {
043        final int i = Character.digit((char) b, URLCodec.RADIX);
044        if (i == -1) {
045            throw new DecoderException("Invalid URL encoding: not a valid digit (radix " + URLCodec.RADIX + "): " + b);
046        }
047        return i;
048    }
049
050}