it.unipmn.di.dcs.common.conversion.Convert.java Source code

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Here is the source code for it.unipmn.di.dcs.common.conversion.Convert.java

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/*
 * Copyright (C) 2007-2012  Marco Guazzone
 *                          [Distributed Computing System (DCS) Group,
 *                           Computer Science Institute,
 *                           Department of Science and Technological Innovation,
 *                           University of Piemonte Orientale,
 *                           Alessandria (Italy)]
 *
 * This file is part of dcj-commons.
 *
 * dcsj-commons is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * dcsj-commons is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with dcsj-commons.  If not, see <http://www.gnu.org/licenses/>.
 */

package it.unipmn.di.dcs.common.conversion;

import org.apache.commons.codec.binary.Base64;

/**
 * Utility class for data conversion.
 *
 * @author <a href="mailto:marco.guazzone@gmail.com">Marco Guazzone</a>
 */
public class Convert {
    /**
     * Converts a Base64 string to a byte array.
     */
    public static byte[] Base64ToBytes(String s) {
        if (s == null) {
            return null;
        }

        //return Base64.Decode( s ); // deprecated
        return Base64.decodeBase64(s.getBytes());
    }

    /**
     * Converts a Base64 byte array to a byte array.
     */
    public static byte[] Base64ToBytes(byte[] data) {
        if (data == null) {
            return null;
        }

        return Base64.decodeBase64(data);
    }

    /**
     * Converts a byte array to a Base64 string.
     */
    public static String BytesToBase64(byte[] bytes) {
        if (bytes == null) {
            return null;
        }

        //return Base64.Encode( bytes ); // deprecated
        return new String(Base64.encodeBase64(bytes));
    }

    /**
     * Converts a byte array to a Base64 byte array.
     */
    public static byte[] BytesToBase64Bytes(byte[] bytes) {
        if (bytes == null) {
            return null;
        }

        return Base64.encodeBase64(bytes);
    }

    /**
     * Converts a hexadecimal string to a byte array.
     */
    public static byte[] HexToBytes(String hexStr) {
        if (hexStr == null || hexStr.length() == 0) {
            return null;
        }

        // Creates an array whose size is half of the string length.
        // (note: one byte is 2 hex digit).
        byte[] bytes = new byte[hexStr.length() / 2];
        int curIndex = 0;
        for (int i = 0; i < hexStr.length(); ++i) {
            curIndex = (i / 2);
            String hexString = hexStr.substring(i, 2);
            byte newByte = Byte.parseByte(hexString, 16);
            bytes[curIndex] = newByte;
            i++;
        }
        return bytes;
    }

    /**
     * Converts a byte array to a hexadecimal string.
     */
    public static String BytesToHex(byte[] bytes) {
        if (bytes == null) {
            return null;
        }

        /* Variant:
        char[] chars = new char[bytes.length * 2];
        for (int i = 0; i < bytes.length; i++)
        {
           int b = bytes[i];
           chars[i * 2] = hexDigits[b >> 4];
           chars[i * 2 + 1] = hexDigits[b & 0xF];
        }
        return new String(chars);
        */

        StringBuffer hexStr = new StringBuffer();
        for (byte b : bytes) {
            hexStr.append(String.format("%2X", b));
        }

        return hexStr.toString();
    }
}