HexConverter.java

/*
 * Copyright 2014 Harald Wellmann.
 *
 * 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.
 */
package org.ops4j.pax.web.jaas.util;


public class HexConverter {

    private static final byte[] HEX_BYTES = new byte[]
        {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};

    /**
     * Take the supplied byte array and convert it to to a byte array of the encoded
     * hex values.
     * <p/>
     * Each byte on the incoming array will be converted to two bytes on the return
     * array.
     *
     * @param toBeConverted - the bytes to be encoded.
     * @return the encoded byte array.
     */
    public static byte[] convertToHexBytes(byte[] toBeConverted) {
        if (toBeConverted == null) {
            throw new NullPointerException("Parameter to be converted can not be null");
        }

        byte[] converted = new byte[toBeConverted.length * 2];
        for (int i = 0; i < toBeConverted.length; i++) {
            byte b = toBeConverted[i];
            converted[i * 2] = HEX_BYTES[b >> 4 & 0x0F];
            converted[i * 2 + 1] = HEX_BYTES[b & 0x0F];
        }

        return converted;
    }
}