Solved

Convert HexaDecimal Strng to Byte Array Using Java

Posted on 2011-02-22
5
876 Views
Last Modified: 2012-05-11
Hello,

I'm trying to find out how to convert a hexadecimal string to a byte array using Java.

For example if I want to display a value such as d079061eff52d88e8ef80db06461466e as "-38, 111, 6, 31, 91, 81, -40, -114, -114, -40, 13, -80, 116, 97, 72, 110" then what do I do. (The above is a made up hex string just for representation here)

I've tried to do this using a class as per the code snippet I've attached here But it prints out something similar to "Ðy\RØŽŽØ
°taHn"

That is not what I want though as I want the numbered format similar to the numbers 38, 111, 6, 31,  etc above.


Any ideas/help on this?

Thanks!
public class CipherTextByteConverter {
	
	public CipherTextByteConverter(){
		
	}
	
    public static void main(String[] args) {

    	CipherTextByteConverter cipherConvert=new CipherTextByteConverter();
    	
        String hexVal = "d079061eff52d88e8ef80db06461466e";
       String value = new String(cipherConvert.hexToBytes(hexVal));
        
        System.out.println(value);

    }	

    public static byte[] hexToBytes(String hexVal) {
        int len = hexVal.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
          data[i / 2] = (byte) ((Character.digit(hexVal.charAt(i), 16) << 4)
      	                             + Character.digit(hexVal.charAt(i+1), 16));
        }
        
        return data;
    }	    
}

Open in new window

0
Comment
Question by:speedygonzalez
  • 2
  • 2
5 Comments
 
LVL 37

Assisted Solution

by:TommySzalapski
TommySzalapski earned 250 total points
ID: 34953536
Convert each byte to an integer not a string. Then display. The problem is that it's interpreting the byte as a character. You want it to think it's an integer.
Something like:
    public static string hexToBytes(String hexVal) {
        int len = hexVal.length();
        byte datum
        string str = ""];
        for (int i = 0; i < len; i += 2) {
          datum = (byte) ((Character.digit(hexVal.charAt(i), 16) << 4)
      	                             + Character.digit(hexVal.charAt(i+1), 16));
        str = str + ", " + String( (int)datum)
        }
        
        return data;
    }	

Open in new window

0
 
LVL 37

Assisted Solution

by:TommySzalapski
TommySzalapski earned 250 total points
ID: 34953542
The syntax might not be perfect, but you should be able to get it from there.
Oh, and change it to
return str;
of course
0
 
LVL 47

Assisted Solution

by:for_yan
for_yan earned 250 total points
ID: 34953567
You just print it differently:
    public class CipherTextByteConverter {

	public CipherTextByteConverter(){

	}

    public static void main(String[] args) {

    	CipherTextByteConverter cipherConvert=new CipherTextByteConverter();

        String hexVal = "d079061eff52d88e8ef80db06461466e";
       String value = new String(cipherConvert.hexToBytes(hexVal));

        byte [] bytes =    cipherConvert.hexToBytes(hexVal);
       for(int j=0;j<bytes.length; j++){
           System.out.print("" + bytes[j]);
       }
        //System.out.println(value);

    }

    public static byte[] hexToBytes(String hexVal) {
        int len = hexVal.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
          data[i / 2] = (byte) ((Character.digit(hexVal.charAt(i), 16) << 4)
      	                             + Character.digit(hexVal.charAt(i+1), 16));
        }

        return data;
    }
}

Open in new window

0
 
LVL 47

Accepted Solution

by:
for_yan earned 250 total points
ID: 34953613
Added commas to separate:

    public class CipherTextByteConverter {

	public CipherTextByteConverter(){

	}

    public static void main(String[] args) {

    	CipherTextByteConverter cipherConvert=new CipherTextByteConverter();

        String hexVal = "d079061eff52d88e8ef80db06461466e";
       String value = new String(cipherConvert.hexToBytes(hexVal));

        byte [] bytes =    cipherConvert.hexToBytes(hexVal);
       for(int j=0;j<bytes.length; j++){
           System.out.print("" + bytes[j] +",");
       }
        //System.out.println(value);

    }

    public static byte[] hexToBytes(String hexVal) {
        int len = hexVal.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
          data[i / 2] = (byte) ((Character.digit(hexVal.charAt(i), 16) << 4)
      	                             + Character.digit(hexVal.charAt(i+1), 16));
        }

        return data;
    }
}

Open in new window

0
 
LVL 92

Expert Comment

by:objects
ID: 34956064
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: Nadia
Linear search (searching each index in an array one by one) works almost everywhere but it is not optimal in many cases. Let's assume, we have a book which has 42949672960 pages. We also have a table of contents. Now we want to read the content on p…
Introduction This article is the first of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article explains our test automation goals. Then rationale is given for the tools we use to a…
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…
This theoretical tutorial explains exceptions, reasons for exceptions, different categories of exception and exception hierarchy.

863 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

25 Experts available now in Live!

Get 1:1 Help Now