How to convert a string representation of a hex dump to a byte array using Java?

0 votes

I am looking for a way to convert a long string (from a dump), that represents hex values into a byte array.

I couldn't have phrased it better than the person that posted the same question here.

But to keep it original, I'll phrase it my own way: suppose I have a string "00A0BF" that I would like interpreted as the

byte[] {0x00,0xA0,0xBf}

what should I do?

I am a Java novice and ended up using BigInteger and watching out for leading hex zeros. But I think it is ugly and I am sure I am missing something simple.

Sep 26, 2018 in Java by Sushmita
• 6,870 points
138 views

1 answer to this question.

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

Reasons why it is an improvement:

  • Safe with leading zeros (unlike BigInteger) and with negative byte values (unlike Byte.parseByte)

  • Doesn't convert the String into a char[], or create StringBuilder and String objects for every single byte.

  • No library dependencies that may not be available

Feel free to add argument checking via assert or exceptions if the argument is not known to be safe.

answered Sep 26, 2018 by sharth
• 3,320 points

Related Questions In Java

0 votes
2 answers

How to convert a java string into byte array

Try using String.getBytes(). It returns a byte[] ...READ MORE

answered 2 days ago in Java by Sirajul
• 19,670 points
46 views
0 votes
2 answers

How to convert an int array to string using tostring method in java?

Use java.util.Arrays: String res = Arrays.toString(array); System.o ...READ MORE

answered Aug 16 in Java by Sirajul
• 19,670 points
191 views
+1 vote
3 answers

How to convert a List to an Array in Java?

Either: Foo[] array = list.toArray(new Foo[list.size()]); or: Foo[] array = ...READ MORE

answered Aug 7, 2018 in Java by Akrati
• 3,150 points
50 views
0 votes
2 answers

How to convert byte array to String and STring to byte array?

The best possible way of conversion between byte[] and String is to ...READ MORE

answered 2 days ago in Java by Sirajul
• 19,670 points
50 views
0 votes
1 answer

How do I convert an input stream into a byte array

There is a simple solution without the ...READ MORE

answered Apr 25, 2018 in Java by developer_1
• 3,280 points
269 views
+5 votes
3 answers

How to execute a python file with few arguments in java?

You can use Java Runtime.exec() to run python script, ...READ MORE

answered Mar 27, 2018 in Java by DragonLord999
• 8,380 points

edited Nov 6, 2018 by Omkar 7,275 views
0 votes
1 answer

How to handle drop downs using Selenium WebDriver in Java

First, find an XPath which will return ...READ MORE

answered Mar 27, 2018 in Selenium by nsv999
• 5,070 points
1,831 views
0 votes
1 answer

What are the differences between getText() and getAttribute() functions in Selenium WebDriver?

See, both are used to retrieve something ...READ MORE

answered Apr 5, 2018 in Selenium by nsv999
• 5,070 points
4,785 views
0 votes
1 answer

How can I convert byte array into hex string in Java?

private final static char[] hexarr = "0123456789ABCDEF".toCharArray(); public ...READ MORE

answered May 24, 2018 in Java by sharth
• 3,320 points
327 views
0 votes
2 answers

How can I convert a String variable to a primitive int in Java

 Here are two ways illustrating this: Integer x ...READ MORE

answered 4 days ago in Java by Sirajul
• 19,670 points
112 views