Mega Code Archive
Hex decoder
<![CDATA[
/*
* Copyright 1998-2000 Sun Microsystems, Inc. All Rights Reserved.
*
* Modified by Tomas Gustavsson
*/
import java.io.*;
import java.math.BigInteger;
/**
* This class implements a hex decoder, decoding a string with hex-characters into
* the binary form.
*
* @version $Id: Hex.java,v 1.4 2004/04/15 07:28:36 hamgert Exp $
*
*/
public class Hex {
static private final char hex[] = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
/**
* Encodar binärt till hex
*
*@param dataStr bin-representation av data
*@return Hex-representation av data
**/
public static String encode(byte[] dataStr) {
StringWriter w = new StringWriter();
for (int i = 0; i < dataStr.length; i++) {
int b = dataStr[i];
w.write(hex[((b >> 4) & 0xF)]);
w.write(hex[((b >> 0) & 0xF)]);
}
return w.toString();
}
/**
* Decodar hex till binärt
*
*@param dataStr Sträng innehållande hex-representation av data
*@return byte[] innhållande binär representation av data
**/
public static byte[] decode(String dataStr) {
if ((dataStr.length() & 0x01) == 0x01)
dataStr = new String(dataStr + "0");
BigInteger cI = new BigInteger(dataStr, 16);
byte[] data = cI.toByteArray();
return data;
} //decode
public static void main(String[] args) {
if (args.length != 3) {
System.out.println("Usage: HexStrToBin enc/dec <infileName> <outfilename>");
System.exit(1);
}
try {
ByteArrayOutputStream os = new ByteArrayOutputStream();
InputStream in = new FileInputStream(args[1]);
int len = 0;
byte buf[] = new byte[1024];
while ((len = in.read(buf)) > 0)
os.write(buf, 0, len);
in.close();
os.close();
byte[] data = null;
if (args[0].equals("dec"))
data = decode(os.toString());
else {
String strData = encode(os.toByteArray());
data = strData.getBytes();
}
FileOutputStream fos = new FileOutputStream(args[2]);
fos.write(data);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
} //main
} // Hex
]]>