| /* |
| * 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> |
| * |
| * @since 1.4 |
| */ |
| class Utils { |
| |
| /** |
| * Radix used in encoding and decoding. |
| */ |
| private static final int RADIX = 16; |
| |
| /** |
| * Returns the numeric value of the character {@code b} 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, RADIX); |
| if (i == -1) { |
| throw new DecoderException("Invalid URL encoding: not a valid digit (radix " + RADIX + "): " + b); |
| } |
| return i; |
| } |
| |
| /** |
| * Returns the upper case hex digit of the lower 4 bits of the int. |
| * |
| * @param b the input int |
| * @return the upper case hex digit of the lower 4 bits of the int. |
| */ |
| static char hexDigit(final int b) { |
| return Character.toUpperCase(Character.forDigit(b & 0xF, RADIX)); |
| } |
| |
| } |