/*

  * 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.net;

 import org.apache.commons.codec.DecoderException;

 /**

  * Utility methods for this package.

  *

  * <p>This class is immutable and thread-safe.</p>

  *

  * @version $Id$

  * @since 1.4

  */

 class Utils {

     /**

      * Returns the numeric value of the character <code>b</code> in radix 16.

      *

      * @param b

      *            The byte to be converted.

      * @return The numeric value represented by the character in radix 16.

      *

      * @throws DecoderException

      *             Thrown when the byte is not valid per {@link Character#digit(char,int)}

      */

     static int digit16(final byte b) throws DecoderException {

         final int i = Character.digit((char) b, URLCodec.RADIX);

         if (i == -1) {

             throw new DecoderException("Invalid URL encoding: not a valid digit (radix " + URLCodec.RADIX + "): " + b);

         }

         return i;

     }

 }