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This is the core Apache Tika™ toolkit library from which all other modules inherit functionality. It also
includes the core facades for the Tika API.
/*
* 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.tika.mime;
/**
*
* A set of Hex encoding and decoding utility methods.
*
*/
public class HexCoDec {
private static final char[] HEX_CHARS = { '0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
/**
* Decode a hex string
*
* @param hexValue
* the string of hex characters
* @return the decode hex string as bytes.
*/
public static byte[] decode(String hexValue) {
return decode(hexValue.toCharArray());
}
/**
* Decode an array of hex chars
*
* @param hexChars
* an array of hex characters.
* @return the decode hex chars as bytes.
*/
public static byte[] decode(char[] hexChars) {
return decode(hexChars, 0, hexChars.length);
}
/**
* Decode an array of hex chars.
*
* @param hexChars
* an array of hex characters.
* @param startIndex
* the index of the first character to decode
* @param length
* the number of characters to decode.
* @return the decode hex chars as bytes.
*/
public static byte[] decode(char[] hexChars, int startIndex, int length) {
if ((length & 1) != 0)
throw new IllegalArgumentException("Length must be even");
byte[] result = new byte[length / 2];
for (int j = 0; j < result.length; j++) {
result[j] = (byte) (hexCharToNibble(hexChars[startIndex++]) * 16 + hexCharToNibble(hexChars[startIndex++]));
}
return result;
}
/**
* Hex encode an array of bytes
*
* @param bites
* the array of bytes to encode.
* @return the array of hex characters.
*/
public static char[] encode(byte[] bites) {
return encode(bites, 0, bites.length);
}
/**
* Hex encode an array of bytes
*
* @param bites
* the array of bytes to encode.
* @param startIndex
* the index of the first character to encode.
* @param length
* the number of characters to encode.
* @return the array of hex characters.
*/
public static char[] encode(byte[] bites, int startIndex, int length) {
char[] result = new char[length * 2];
for (int i = 0, j = 0; i < length; i++) {
int bite = bites[startIndex++] & 0xff;
result[j++] = HEX_CHARS[bite >> 4];
result[j++] = HEX_CHARS[bite & 0xf];
}
return result;
}
/**
* Internal method to turn a hex char into a nibble.
*/
private static int hexCharToNibble(char ch) {
if ((ch >= '0') && (ch <= '9')) {
return ch - '0';
} else if ((ch >= 'a') && (ch <= 'f')) {
return ch - 'a' + 10;
} else if ((ch >= 'A') && (ch <= 'F')) {
return ch - 'A' + 10;
} else {
throw new IllegalArgumentException("Not a hex char - '" + ch + "'");
}
}
}