/****************************************************************************
* Copyright (C) 2012 ecsec GmbH.
* All rights reserved.
* Contact: ecsec GmbH (info@ecsec.de)
*
* This file is part of the Open eCard App.
*
* GNU General Public License Usage
* This file may be used under the terms of the GNU General Public
* License version 3.0 as published by the Free Software Foundation
* and appearing in the file LICENSE.GPL included in the packaging of
* this file. Please review the following information to ensure the
* GNU General Public License version 3.0 requirements will be met:
* http://www.gnu.org/copyleft/gpl.html.
*
* Other Usage
* Alternatively, this file may be used in accordance with the terms
* and conditions contained in a signed written agreement between
* you and ecsec GmbH.
*
***************************************************************************/
package org.openecard.common.util;
/**
* A set of utility functions for integers.
*
* @author Moritz Horsch <horsch at cdc.informatik.tu-darmstadt.de>
* @author Tobias Wich <tobias.wich@ecsec.de>
*/
public class IntegerUtils {
/**
* Convert an integer to a byte array.
*
* @param value integer to be converted
* @return byte[]
*/
public static byte[] toByteArray(int value) {
return toByteArray(value, 8);
}
/**
* Convert an integer to a byte array with a given bit size per byte.
*
* @param value integer to be converted
* @param numBits Number of bits
* @return byte[]
*/
public static byte[] toByteArray(int value, int numBits) {
return toByteArray(value, numBits, true);
}
/**
* Convert an integer to a byte array with a given bit size per byte.
*
* @param value integer to be converted
* @param numBits Number of bits
* @param bigEndian {@code true} when output should be in Big Endian, {@code false} for Little Endian.
* @return byte[]
*/
public static byte[] toByteArray(int value, int numBits, boolean bigEndian) {
return LongUtils.toByteArray(value, numBits, bigEndian);
}
/**
* Convert an integer to a byte array. If the resulting array contains less bytes than 4 bytes, 0 bytes are prepended if the flag is set.
*
* @param value integer to be converted
* @param padArrayToTypeLength
* @return byte[]
*/
public static byte[] toByteArray(int value, boolean padArrayToTypeLength) {
return toByteArray(value, padArrayToTypeLength, true);
}
/**
* Convert an integer to a byte array. If the resulting array contains less bytes than 4 bytes, 0 bytes are prepended if the flag is set.
*
* @param value integer to be converted
* @param padArrayToTypeLength
* @param bigEndian {@code true} when output should be in Big Endian, {@code false} for Little Endian.
* @return byte[]
*/
public static byte[] toByteArray(int value, boolean padArrayToTypeLength, boolean bigEndian) {
byte[] result = toByteArray(value, 8, bigEndian);
if (padArrayToTypeLength && result.length < 4) {
result = ByteUtils.concatenate(new byte[4 - result.length], result);
}
return result;
}
}