org.apache.commons.codec.net.Utils Maven / Gradle / Ivy
/*
* 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.
*
* This class is immutable and thread-safe.
*
* @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));
}
}