如何将字节数组转换为人类可读格式？

Question

I am using "Blowfish" algorithm to encrypt and decrypt the contents of the text. I am embedding the encrypted contents in the image but while extracting I am getting the byte array which I am passing it to method update of class Cipher .

But the method returns me byte array which I want to convert back into Human readable form.
When I use write method of FileOutputStream it is working fine when a filename is provided.
But now I want to print it on the console in the human readable format. How to get through this? I have tried for ByteArrayOutputStream too. But didn't work well.

Thank you.

Answer 1

If all you want to do is see the numeric values you can loop through the array and print each byte:

for(byte foo : arr){
    System.out.print(foo + " ");
}

Or if you want to see hex values you can use printf :

System.out.printf("%02x ", foo);

If you want to see the string that the byte array represents you can just do

System.out.print(new String(arr));

Answer 2

You can convert the bytearray into a string containing the hex values of the bytes using this method. This even works on java < 6

public class DumpUtil {

     private static final String HEX_DIGITS = "0123456789abcdef";

     public static String toHex(byte[] data) {
        StringBuffer buf = new StringBuffer();

        for (int i = 0; i != data.length; i++) {
            int v = data[i] & 0xff;

            buf.append(HEX_DIGITS.charAt(v >> 4));
            buf.append(HEX_DIGITS.charAt(v & 0xf));

            buf.append(" ");
        }

        return buf.toString();
    }   
}

Answer 3

byte[] byteArray = new byte[] {87, 79, 87, 46, 46, 46};

String value = new String(byteArray);

Answer 4

byte[] data = new byte[] {1, 2, 3, 4};
System.out.printf( Arrays.toString( data ) );

[1, 2, 3, 4]

Answer 5

It's better to do a hexDump that byte array

private static final byte[] HEX_CHAR = new byte[] { '0', '1', '2', '3',
            '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
public static final String dumpBytes(byte[] buffer) {
        if (buffer == null) {
            return "";
        }
        StringBuilder sb = new StringBuilder();
        sb.setLength(0);
        for (int i = 0; i < buffer.length; i++) {
            sb.append((char) (HEX_CHAR[(buffer[i] & 0x00F0) >> 4]))
                    .append((char) (HEX_CHAR[buffer[i] & 0x000F])).append(' ');
        }
        return sb.toString();
    }