Java Hex Convert To fromHex(final String hex)

Description

from Hex

License

Apache License

Declaration

public static byte fromHex(final String hex) throws IllegalArgumentException 

Method Source Code

//package com.java2s;
/*//from  w w w  .  j a va 2  s.c  om
 *   Copyright 2007 skynamics AG
 *
 *   Licensed 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.
 */

public class Main {
    public static byte fromHex(final String hex) throws IllegalArgumentException {
        if (hex == null)
            throw new IllegalArgumentException("Hex strings may not be null");

        if (hex.length() % 2 != 0)
            throw new IllegalArgumentException("Hex strings must have length 2");

        return (byte) (dehex(hex.charAt(0)) << 4 | dehex(hex.charAt(1)));
    }

    private static int dehex(char c) throws IllegalArgumentException {
        int v = Character.digit(c, 16);
        if (v == -1)
            throw new IllegalArgumentException("'" + c + "' is no valid hex digit");
        return v;
    }
}

Related

1. fromHex(char c)
2. fromHex(char hi, char lo)
3. fromHex(CharSequence cs)
4. fromHex(final CharSequence s)
5. fromHex(final String hex)
6. fromHex(final String hexValue)
7. fromHex(final String s)
8. fromHex(final String string, final int offset, final int count)
9. fromHex(String bytesString)