Hex String to Image

Question

I have a hex string which looks like:

String hexImage =\"0xFFD8FFE000104A46494600010200006400640000FFEC00114475636B79000100040000003C...\"

Whi

Answer 1

Normally, each byte is represented by 2 hex digits, therefore, if you have an odd number of digits in your HEX string, then something is wrong with it. You can try padding it with 0 in the beginning, such as this:

String hexImage ="0xFFD8FFE000104A46494600010200006400640000FFEC00114475636B79000100040000003C...";
if(hexImage.length()%2 == 1)
    hexImage = "0x0" + hexImage.substring(2);

or at the end, such as this:

String hexImage ="0xFFD8FFE000104A46494600010200006400640000FFEC00114475636B79000100040000003C...";
if(hexImage.length()%2 == 1)
    hexImage += "0";

However this is not guaranteed to produce a proper image.

On the whole, you should check how you get your hex string. A proper byte sequence should always contain an even number of hex digits.

EDIT: In addition, as Peter Lawrey indicated in his comment, you should check whether the decode method expects 0x in front of the string.

Answer 2

for even length string

 public static byte[] hexStringToByteArray(String str) {
    try {


        String s = str;
        int len = s.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            if (i == len - 1) {
                 System.out.println("in correct");                   
            } else {

                data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
                        + Character.digit(s.charAt(i + 1), 16));


            }
        }
        return data;
    } catch (StringIndexOutOfBoundsException sex) {

        writeDirtyData(str.substring(0, str.indexOf(",")));
    }
    return null;
}

Non of Odd hex string is correct. Check source from you get this string . It is because of truncation of string due to limit no of characters. If String is image is stored in database then retrieve it using program not using any tools

I was having same problem with .net and MSSQL and by using webservice and Java Client I tried all conversion and library including axis and util jpg.