Mega Code Archive
Byte-Array Conversion Utility Functions
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import java.io.UnsupportedEncodingException;
/**
* <p>Byte-Array Conversion Utility Functions.</p>
*
* $Id: ByteUtils.java,v 1.6 2005/06/16 19:58:58 mokhov Exp $
*
* @version $Revision: 1.6 $
* @author Serguei Mokhov
* @since 0.3.0
*/
public class ByteUtils
{
/**
* Allow derivatives.
*/
protected ByteUtils()
{
}
/**
* Converts a byte array to short value.
* Equivalent to byteArrayToShort(paRawBytes, 0, pbBigEndian);
*
* @param paRawBytes the byte array
* @param pbBigEndian true if the bytes are in Big-endian order; false otherwise
*
* @return short representation of the bytes
*/
public static short byteArrayToShort(byte[] paRawBytes, boolean pbBigEndian)
{
return byteArrayToShort(paRawBytes, 0, pbBigEndian);
}
/**
* Converts a portion of a byte array with given offset to short value.
*
* @param paRawBytes the byte array
* @param piOffset offset in the original array to start reading bytes from
* @param pbBigEndian true if the bytes are in Big-endian order; false otherwise
*
* @return short representation of the bytes
*/
public static short byteArrayToShort(byte[] paRawBytes, int piOffset, boolean pbBigEndian)
{
int iRetVal = -1;
// TODO: revisit this: should we silently add missing byte and should
// we ingnore excessing bytes?
if(paRawBytes.length < piOffset + 2)
return -1;
int iLow;
int iHigh;
if(pbBigEndian)
{
iLow = paRawBytes[piOffset + 1];
iHigh = paRawBytes[piOffset + 0];
}
else
{
iLow = paRawBytes[piOffset + 0];
iHigh = paRawBytes[piOffset + 1];
}
// Merge high-order and low-order byte to form a 16-bit double value.
iRetVal = (iHigh << 8) | (0xFF & iLow);
return (short)iRetVal;
}
/**
* Converts a byte array to int value.
* Equivalent to intArrayToShort(paRawBytes, 0, pbBigEndian);
*
* @param paRawBytes the byte array
* @param pbBigEndian true if the bytes are in Big-endian order; false otherwise
*
* @return int representation of the bytes
*/
public static int byteArrayToInt(byte[] paRawBytes, boolean pbBigEndian)
{
return byteArrayToInt(paRawBytes, 0, pbBigEndian);
}
/**
* Converts a portion of a byte array with given offset to int value.
*
* @param paRawBytes the byte array
* @param piOffset offset in the original array to start reading bytes from
* @param pbBigEndian true if the bytes are in Big-endian order; false otherwise
*
* @return int representation of the bytes
*/
public static int byteArrayToInt(byte[] paRawBytes, int piOffset, boolean pbBigEndian)
{
int iRetVal = -1;
if(paRawBytes.length < piOffset + 4)
return iRetVal;
int iLowest;
int iLow;
int iMid;
int iHigh;
if(pbBigEndian)
{
iLowest = paRawBytes[piOffset + 3];
iLow = paRawBytes[piOffset + 2];
iMid = paRawBytes[piOffset + 1];
iHigh = paRawBytes[piOffset + 0];
}
else
{
iLowest = paRawBytes[piOffset + 0];
iLow = paRawBytes[piOffset + 1];
iMid = paRawBytes[piOffset + 2];
iHigh = paRawBytes[piOffset + 3];
}
// Merge four bytes to form a 32-bit int value.
iRetVal = (iHigh << 24) | (iMid << 16) | (iLow << 8) | (0xFF & iLowest);
return iRetVal;
}
/**
* Converts an int value to a byte array.
*
* @param piValueToConvert the original integer
* @param pbBigEndian true if the bytes are in Big-endian order; false otherwise
*
* @return byte[] representation of the int
*/
public static byte[] intToByteArray(int piValueToConvert, boolean pbBigEndian)
{
byte[] aRetVal = new byte[4];
byte iLowest;
byte iLow;
byte iMid;
byte iHigh;
iLowest = (byte)(piValueToConvert & 0xFF);
iLow = (byte)((piValueToConvert >> 8) & 0xFF);
iMid = (byte)((piValueToConvert >> 16) & 0xFF);
iHigh = (byte)((piValueToConvert >> 24) & 0xFF);
if(pbBigEndian)
{
aRetVal[3] = iLowest;
aRetVal[2] = iLow;
aRetVal[1] = iMid;
aRetVal[0] = iHigh;
}
else
{
aRetVal[0] = iLowest;
aRetVal[1] = iLow;
aRetVal[2] = iMid;
aRetVal[3] = iHigh;
}
return aRetVal;
}
/**
* Converts a byte array to String value.
* Cleans up non-word characters along the way.
*
* Equivalent to byteArrayToString(paRawBytes, 0, paRawBytes.length);
*
* @param paRawBytes the byte array, non-UNICODE
*
* @return UNICODE String representation of the bytes
*/
public static String byteArrayToString(byte[] paRawBytes)
{
return byteArrayToString(paRawBytes, 0, paRawBytes.length);
}
/**
* Converts a portion of a byte array to String value.
* Cleans up non-word characters along the way.
*
* @param paRawBytes the byte array, non-UNICODE
* @param piOffset offset in the original array to start reading bytes from
* @param piLength how many bytes of the array paramter to interpret as String
*
* @return UNICODE String representation of the bytes with trailing garbage stripped;
* "" if array length is less than piOffset + piLength;
* "" if the generatied string begins with garbage
*/
public static String byteArrayToString(byte[] paRawBytes, int piOffset, int piLength)
{
if(paRawBytes.length < piOffset + piLength)
return "";
String oBeautifulString = new String(paRawBytes, piOffset, piLength);
int i = 0;
if(oBeautifulString.matches("^\\W") == true)
oBeautifulString = "";
else
{
for(i = piOffset; i < piOffset + piLength; i++)
{
if(paRawBytes[i] < 32 || paRawBytes[i] > 128)
break;
}
oBeautifulString = oBeautifulString.substring(0, i - piOffset);
}
return oBeautifulString;
}
/**
* Converts a String value to a byte array in US-ASCII charset.
*
* Equivalent to stringToByteArray(pstrStringToConvert, "US-ASCII");
*
* @param pstrStringToConvert the original string
*
* @return null-terminated byte[] representation of the String
*/
public static byte[] stringToByteArray(String pstrStringToConvert)
{
return stringToByteArray(pstrStringToConvert, "US-ASCII");
}
/**
* Attempts to convert a String value to a byte array in specified charset.
* If the charset is invalid, returns plain byte-representation of the host environment.
*
* @param pstrStringToConvert the original string
* @param pstrCharSet characted set to assume for the original string
*
* @return null-terminated byte[] representation of the String
*/
public static byte[] stringToByteArray(String pstrStringToConvert, String pstrCharSet)
{
byte[] aRecordData = null;
try
{
aRecordData = (pstrStringToConvert + '\0').getBytes(pstrCharSet);
}
catch(UnsupportedEncodingException e)
{
System.err.println("WARNING: " + e);
aRecordData = (pstrStringToConvert + '\0').getBytes();
}
return aRecordData;
}
/**
* Returns source code revision information.
* @return revision string
*/
public static String getMARFSourceCodeRevision()
{
return "$Revision: 1.6 $";
}
}
// EOF
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