How to convert HexString To jpg image in java?

Question

Hi I have a hex String I need to convert that into jpg image please explain me how to do that i have done like this.This Hex String I need to convert into the jpg image,I am trying here but its not coming.

 String hex="ff d8 ff e0 00 11 4a 46 49 46 00 01 01 01 00 00 00 00 00 00 0a ff db 00 43 00 08 06 06 07 06 05 08 07 07 07 09 09 08 0a 0c 14 0d 0c 0b 0b 0c 19 12 13 0f 14 1d 1a 1f 1e 1d 1a 1c 1c 20 24 2e 27 20 22 2c 23 1c 1c 28 37 29 2c 30 31 34 34 34 1f 27 39 3d 38 32 3c 2e 33 34 32 ff db 00 43 01 09 09 09 0c 0b 0c 18 0d 0d 18 32 21 1c 21 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 ff c4 00 1f 00 00 01 05 01 01 01 01 01 01 00 00 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 0a 0b ff c4 00 b5 10 00 02 01 03 03 02 04 03 05 05 04 04 00 00 01 7d 01 02 03 00 04 11 05 12 21 31 41 06 13 51 61 07 22 71 14 32 81 91 a1 08 23 42 b1 c1 15 52 d1 f0 24 33 62 72 82 09 0a 16 17 18 19 1a 25 26 27 28 29 2a 34 35 36 37 38 39 3a 43 44 45 46 47 48 49 4a 53 54 55 56 57 58 59 5a 63 64 65 66 67 68 69 6a 73 74 75 76 77 78 79 7a 83 84 85 86 87 88 89 8a 92 93 94 95 96 97 98 99 9a a2 a3 a4 a5 a6 a7 a8 a9 aa b2 b3 b4 b5 b6 b7 b8 b9 ba c2 c3 c4 c5 c6 c7 c8 c9 ca d2 d3 d4 d5 d6 d7 d8 d9 da e1 e2 e3 e4 e5 e6 e7 e8 e9 ea f1 f2 f3 f4 f5 f6 f7 f8 f9 fa ff c4 00 1f 01 00 03 01 01 01 01 01 01 01 01 01 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 0a 0b ff c4 00 b5 11 00 02 01 02 04 04 03 04 07 05 04 04 00 01 02 77 00 01 02 03 11 04 05 21 31 06 12 41 51 07 61 71 13 22 32 81 08 14 42 91 a1 b1 c1 09 23 33 52 f0 15 62 72 d1 0a 16 24 34 e1 25 f1 17 18 19 1a 26 27 28 29 2a35 36 37 38 39 3a 43 44 45 46 47 48 49 4a 53 54 55 56 57 58 59 5a 63 64 65";
//            String sb = "0d 02 01 02 4e 52 30 39 47 30 35 36 31 38 00 03 00 fa 01 95 e4 53 c0 a8 51 b1 53 a3 03 40 89 54 66 9c ee 10 01 de 9a 5c 22 e6 a0 2c 5d b2 69 8c 9d 79 e6 a5 41 50 c6 78 ab 31 8c 8a 00 72 83 53 2a e0 67 14 d0 2a 54 1b 85 00 00 76 a6 b4 64 1e 95 32 a1 c8 a5 90 f3 81 da 98 15 88 c7 51 54 6e 63 cb 1e 3a d6 99 19 19 ef 55 6e 13 2b 91 49 89 98 2f a7 49 b8 95 20 8a 88 d9 cc b9 f9 0d 6d 85 e6 9e 23 e3 a5 06 7c a6 02 c6 e8 c3 2a 72 0d 74 90 1d d1 29 f5 14 cf 29 5b 82 01 fa 8a 9d 14 00 00 e0 50 38 ad 46 4c 38 15 89 7a b8 9c fa 11 5b f2 2e 56 a9 5c e9 ad 39 0e 18 03 8e f4 8a 68 c4 14 d2 39 ad 07 d2 ae 17 a0 0d f4 35 5d ed 27 4f bd 1b 0f c2 99 9d 88 06 41 ae 9f 4e 19 b2 88 fb 57 36 54 83 c8 23 eb c5 74 da 70 c5 94 7f 4a 07 1d cb 2c 3e 53 58 77 1c ca 45 6e 37 dd 35 89 38 fd e9 a1 97 2d 88 76 d1 8a 76 29 c8 bb 98 52 32 23 da 4f 6a 96 38 01 19 6e 95 21 c0 e0 0a 98 0d d1 0c 75 14 0a c4 b6 d1 a0 8f 81 8c d3 9d 76 1a 92 24 21 00 a8 e7 38 fc 29 9b c7 62 85 c9 dc f8 f4 aa f8 a7 bb 65 89 a6 1e b4 8c a5 ab 0a 43 41 a6 f7 a0 43 5e 95 54 e0 50 06 48 06 a4 c7 14 0e 28 85 86 2a 32 78 a9 5e a0 90 e0 52 35 7b 12 e2 81 4b 8e 69 71 4c 60 bd 6a 74 a8 50 73 53 31 c0 da 3a d0 00 cd b8 e0 74 14 a0 8c e3 bd 20 18 1c 75 a6 a9 cb 8d c3 9c d3 02 c4 7c 1a b8 83 8a aa 8a 59 b8 ab 89 c0 02 80 1e 38 a5 52 41 e2 90 0a 51 40 0f f3 1b 34 ed e1 ba f5 a8 a9 71 40 12 16 e3 02 a2 75 ca 9a 78 a5 c1 34 01 45 46 3a d4 8b 43 ae d9 0f bd 0b 40 89 00 14 f0 05 31 4d 48 a2 81 8e db 9a 70 5a 45 19 a9 00 a6 16 1a 12 83 1e 6a 40 29 c1 68 15 91 58 db 46 df 79 14 fe 15 24 71 88 d7 6a 8c 01 da a6 c5 21 5a 01 22 0d 0a 2a 4b 57 00 0f 00 01 82 03 00 00 0d 0a ";
//            String raw_DeviceId = sb.substring(38, 1040);
            byte[] b = HexStringToByteArray(hex);
//            imageInFile.read(b);
            for (int i = 0; i < b.length; i++) {
                byte c = b[i];
                System.out.println("c = " + c);

            }
            /*
             * Converting Image byte array into Base64 String 
             */
            String imageDataString = encodeImage(b);
            /*
             * Converting a Base64 String into Image byte array 
             */
            byte[] imageByteArray = decodeImage(imageDataString);
            /*
             * Write a image byte array into file system  
             */
            FileOutputStream imageOutFile = new FileOutputStream("D:/img6.jpg");
            imageOutFile.write(imageByteArray);

            imageInFile.close();
            imageOutFile.close();

            System.out.println("Image Successfully Manipulated!");
        } catch (FileNotFoundException e) {
            System.out.println("Image not found" + e);
        } catch (IOException ioe) {
            System.out.println("Exception while reading the Image " + ioe);
        }

    }

    /**
     * Encodes the byte array into base64 string
     *
     * @param imageByteArray - byte array
     * @return String a {@link java.lang.String}
     */
    public static String encodeImage(byte[] imageByteArray) {
        return Base64.encodeBase64URLSafeString(imageByteArray);
    }

    /**
     * Decodes the base64 string into byte array
     *
     * @param imageDataString - a {@link java.lang.String}
     * @return byte array
     */
    public static byte[] decodeImage(String imageDataString) {
        return Base64.decodeBase64(imageDataString);
    }

}

And HexString to bytearray convertion:

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

Update:

 String hex = "ff d8 ff e0 00 11 4a 46 49 46 00 01 01 01 00 00 00 00 00 00 0a ff db 00 43 00 08 06 06 07 06 05 08 07 07 07 09 09 08 0a 0c 14 0d 0c 0b 0b 0c 19 12 13 0f 14 1d 1a 1f 1e 1d 1a 1c 1c 20 24 2e 27 20 22 2c 23 1c 1c 28 37 29 2c 30 31 34 34 34 1f 27 39 3d 38 32 3c 2e 33 34 32 ff db 00 43 01 09 09 09 0c 0b 0c 18 0d 0d 18 32 21 1c 21 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 ff c4 00 1f 00 00 01 05 01 01 01 01 01 01 00 00 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 0a 0b ff c4 00 b5 10 00 02 01 03 03 02 04 03 05 05 04 04 00 00 01 7d 01 02 03 00 04 11 05 12 21 31 41 06 13 51 61 07 22 71 14 32 81 91 a1 08 23 42 b1 c1 15 52 d1 f0 24 33 62 72 82 09 0a 16 17 18 19 1a 25 26 27 28 29 2a 34 35 36 37 38 39 3a 43 44 45 46 47 48 49 4a 53 54 55 56 57 58 59 5a 63 64 65 66 67 68 69 6a 73 74 75 76 77 78 79 7a 83 84 85 86 87 88 89 8a 92 93 94 95 96 97 98 99 9a a2 a3 a4 a5 a6 a7 a8 a9 aa b2 b3 b4 b5 b6 b7 b8 b9 ba c2 c3 c4 c5 c6 c7 c8 c9 ca d2 d3 d4 d5 d6 d7 d8 d9 da e1 e2 e3 e4 e5 e6 e7 e8 e9 ea f1 f2 f3 f4 f5 f6 f7 f8 f9 fa ff c4 00 1f 01 00 03 01 01 01 01 01 01 01 01 01 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 0a 0b ff c4 00 b5 11 00 02 01 02 04 04 03 04 07 05 04 04 00 01 02 77 00 01 02 03 11 04 05 21 31 06 12 41 51 07 61 71 13 22 32 81 08 14 42 91 a1 b1 c1 09 23 33 52 f0 15 62 72 d1 0a 16 24 34 e1 25 f1 17 18 19 1a 26 27 28 29 2a35 36 37 38 39 3a 43 44 45 46 47 48 49 4a 53 54 55 56 57 58 59 5a 63 64 65";
//            String sb = "0d 02 01 02 4e 52 30 39 47 30 35 36 31 38 00 03 00 fa 01 95 e4 53 c0 a8 51 b1 53 a3 03 40 89 54 66 9c ee 10 01 de 9a 5c 22 e6 a0 2c 5d b2 69 8c 9d 79 e6 a5 41 50 c6 78 ab 31 8c 8a 00 72 83 53 2a e0 67 14 d0 2a 54 1b 85 00 00 76 a6 b4 64 1e 95 32 a1 c8 a5 90 f3 81 da 98 15 88 c7 51 54 6e 63 cb 1e 3a d6 99 19 19 ef 55 6e 13 2b 91 49 89 98 2f a7 49 b8 95 20 8a 88 d9 cc b9 f9 0d 6d 85 e6 9e 23 e3 a5 06 7c a6 02 c6 e8 c3 2a 72 0d 74 90 1d d1 29 f5 14 cf 29 5b 82 01 fa 8a 9d 14 00 00 e0 50 38 ad 46 4c 38 15 89 7a b8 9c fa 11 5b f2 2e 56 a9 5c e9 ad 39 0e 18 03 8e f4 8a 68 c4 14 d2 39 ad 07 d2 ae 17 a0 0d f4 35 5d ed 27 4f bd 1b 0f c2 99 9d 88 06 41 ae 9f 4e 19 b2 88 fb 57 36 54 83 c8 23 eb c5 74 da 70 c5 94 7f 4a 07 1d cb 2c 3e 53 58 77 1c ca 45 6e 37 dd 35 89 38 fd e9 a1 97 2d 88 76 d1 8a 76 29 c8 bb 98 52 32 23 da 4f 6a 96 38 01 19 6e 95 21 c0 e0 0a 98 0d d1 0c 75 14 0a c4 b6 d1 a0 8f 81 8c d3 9d 76 1a 92 24 21 00 a8 e7 38 fc 29 9b c7 62 85 c9 dc f8 f4 aa f8 a7 bb 65 89 a6 1e b4 8c a5 ab 0a 43 41 a6 f7 a0 43 5e 95 54 e0 50 06 48 06 a4 c7 14 0e 28 85 86 2a 32 78 a9 5e a0 90 e0 52 35 7b 12 e2 81 4b 8e 69 71 4c 60 bd 6a 74 a8 50 73 53 31 c0 da 3a d0 00 cd b8 e0 74 14 a0 8c e3 bd 20 18 1c 75 a6 a9 cb 8d c3 9c d3 02 c4 7c 1a b8 83 8a aa 8a 59 b8 ab 89 c0 02 80 1e 38 a5 52 41 e2 90 0a 51 40 0f f3 1b 34 ed e1 ba f5 a8 a9 71 40 12 16 e3 02 a2 75 ca 9a 78 a5 c1 34 01 45 46 3a d4 8b 43 ae d9 0f bd 0b 40 89 00 14 f0 05 31 4d 48 a2 81 8e db 9a 70 5a 45 19 a9 00 a6 16 1a 12 83 1e 6a 40 29 c1 68 15 91 58 db 46 df 79 14 fe 15 24 71 88 d7 6a 8c 01 da a6 c5 21 5a 01 22 0d 0a 2a 4b 57 00 0f 00 01 82 03 00 00 0d 0a ";
//            String raw_DeviceId = sb.substring(38, 1040);
//            byte[] b = HexStringToByteArray(hex);
////            imageInFile.read(b);
//            for (int i = 0; i < b.length; i++) {
//                byte c = b[i];
//                System.out.println("c = " + c);
//
//            }

            Font font = new Font("Arial", Font.PLAIN, 12);
            BufferedImage img = new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);
            Graphics2D g2d = img.createGraphics();
            FontMetrics fm = g2d.getFontMetrics(font);
            g2d.dispose();

            int width = fm.stringWidth(hex);
            int height = fm.getHeight();
            img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            g2d = img.createGraphics();
            g2d.setColor(Color.WHITE);
            g2d.fillRect(0, 0, width, height);
            g2d.setColor(Color.BLACK);
            g2d.setFont(font);
            g2d.drawString(hex, 0, fm.getAscent());
            g2d.dispose();

            try {
                ImageIO.write(img, "jpg", new File("Hex.jpg"));
            } catch (IOException ex) {
                ex.printStackTrace();
            }

Answer 1

You have a kind of chicken and egg issue. In order to generate the image, you will need to know how big to make the image. In order to calculate this information, you will need a Graphics context from an image in order to ascertain the FontMetrics for the given Graphics context...

The following example simple creates a 1x1 BufferedImage which is used to obtain a reference to the FontMetrics, which is used to calculate the required width/height of the String in question.

This is then used to create a new instance of the BufferedImage at the correct size and the String is rendered to it.

It is then saved to a jpg file...

A small snippet of the output image...

String hex="ff d8 ff e0 00 11 4a 46 49 46 00 01 01 01 00 00 00 00 00 00 0a ff db 00 43 00 08 06 06 07 06 05 08 07 07 07 09 09 08 0a 0c 14 0d 0c 0b 0b 0c 19 12 13 0f 14 1d 1a 1f 1e 1d 1a 1c 1c 20 24 2e 27 20 22 2c 23 1c 1c 28 37 29 2c 30 31 34 34 34 1f 27 39 3d 38 32 3c 2e 33 34 32 ff db 00 43 01 09 09 09 0c 0b 0c 18 0d 0d 18 32 21 1c 21 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 32 ff c4 00 1f 00 00 01 05 01 01 01 01 01 01 00 00 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 0a 0b ff c4 00 b5 10 00 02 01 03 03 02 04 03 05 05 04 04 00 00 01 7d 01 02 03 00 04 11 05 12 21 31 41 06 13 51 61 07 22 71 14 32 81 91 a1 08 23 42 b1 c1 15 52 d1 f0 24 33 62 72 82 09 0a 16 17 18 19 1a 25 26 27 28 29 2a 34 35 36 37 38 39 3a 43 44 45 46 47 48 49 4a 53 54 55 56 57 58 59 5a 63 64 65 66 67 68 69 6a 73 74 75 76 77 78 79 7a 83 84 85 86 87 88 89 8a 92 93 94 95 96 97 98 99 9a a2 a3 a4 a5 a6 a7 a8 a9 aa b2 b3 b4 b5 b6 b7 b8 b9 ba c2 c3 c4 c5 c6 c7 c8 c9 ca d2 d3 d4 d5 d6 d7 d8 d9 da e1 e2 e3 e4 e5 e6 e7 e8 e9 ea f1 f2 f3 f4 f5 f6 f7 f8 f9 fa ff c4 00 1f 01 00 03 01 01 01 01 01 01 01 01 01 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 0a 0b ff c4 00 b5 11 00 02 01 02 04 04 03 04 07 05 04 04 00 01 02 77 00 01 02 03 11 04 05 21 31 06 12 41 51 07 61 71 13 22 32 81 08 14 42 91 a1 b1 c1 09 23 33 52 f0 15 62 72 d1 0a 16 24 34 e1 25 f1 17 18 19 1a 26 27 28 29 2a35 36 37 38 39 3a 43 44 45 46 47 48 49 4a 53 54 55 56 57 58 59 5a 63 64 65";

Font font = new Font("Arial", Font.PLAIN, 12);
BufferedImage img = new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = img.createGraphics();
FontMetrics fm = g2d.getFontMetrics(font);
g2d.dispose();

int width = fm.stringWidth(hex);
int height = fm.getHeight();
img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
g2d = img.createGraphics();
g2d.setColor(Color.WHITE);
g2d.fillRect(0, 0, width, height);
g2d.setColor(Color.BLACK);
g2d.setFont(font);
g2d.drawString(hex, 0, fm.getAscent());
g2d.dispose();

try {
    ImageIO.write(img, "jpg", new File("Hex.jpg"));
} catch (IOException ex) {
    ex.printStackTrace();
}