Java Hex Convert To fromHexString(String hexString)

Description

Converts the hex string to a byte array.

License

Open Source License

Parameter

Parameter	Description
hexString	the string to decode. Must have an even number of characters, each pair of which represents a hexadecimal byte.

Exception

Parameter	Description
NumberFormatException	if the string can not be parsed as asequence of hexadecimal digits for any reason.

Return

a numerical representation of the input string.

Declaration

public static byte[] fromHexString(String hexString) throws NumberFormatException 

Method Source Code

//package com.java2s;
/*// ww  w  .j  a  v a 2  s  . c  o m
 * TextUtilities.java (Class: com.madphysicist.tools.util.TextUtilities)
 *
 * Mad Physicist JTools Project (General Purpose Utilities)
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2012 by Joseph Fox-Rabinovitz
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

public class Main {
    /**
     * Converts the hex string to a byte array. The string must have an even
     * number of digits, each of which must be a valid hexadecimal digit. Every
     * two digits represent a successive byte. This method is an almost exact
     * inverse of {@link #toHexString(byte[])}. Calling {@code
     * toHexString(fromHexString(hexString))} will return the original string,
     * up to the case of the hexadecimal digits.
     *
     * @param hexString the string to decode. Must have an even number of
     * characters, each pair of which represents a hexadecimal byte.
     * @return a numerical representation of the input string.
     * @throws NumberFormatException if the string can not be parsed as a
     * sequence of hexadecimal digits for any reason.
     * @since 1.0.0
     */
    public static byte[] fromHexString(String hexString) throws NumberFormatException {
        if (hexString.length() % 2 != 0) {
            throw new NumberFormatException("odd number of digits: " + hexString);
        }
        byte[] bytes = new byte[hexString.length() / 2];
        for (int i = 0; i < bytes.length; i++) {
            char d1 = hexString.charAt(i * 2);
            char d2 = hexString.charAt(i * 2 + 1);
            if (Character.digit(d1, 16) < 0 || Character.digit(d2, 16) < 0) {
                throw new NumberFormatException("not a hex string" + hexString);
            }
            bytes[i] = (byte) (Integer.parseInt("" + d1 + d2, 16) & 0xFF);
        }
        return bytes;
    }
}

Related

1. fromHexString(String encoded)
2. fromHexString(String encoded)
3. fromHexString(String hex)
4. fromHexString(String hex)
5. fromHexString(String hexString)
6. fromHexString(String hexString)
7. fromHexString(String hexString)
8. fromHexString(String in)
9. fromHexString(String input)