java.lang.NumberFormatException: For input string: "010010101101111111"

Question

I have been trying to hide an image in another image(both of same type) by making changes in the pixels.But it gives an error like this:

Exception in thread "main" java.lang.NumberFormatException: For input 
       string: "010010101101111111"
    at java.lang.NumberFormatException.forInputString(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at Image.main(Image.java:160)**

The code is shown as below:

public class Image {




public static void main(String argv[]) throws Exception

{

    String imageFile1 = "C:/Users/Desktop/1.jpg";
    String imageFile2 = "C:/Users/Desktop/2.jpg";


    File file1 = new File(imageFile1);
    FileInputStream fis1 = null;
    try {
        fis1 = new FileInputStream(imageFile1);
    } catch (FileNotFoundException e2) {
        // TODO Auto-generated catch block
        e2.printStackTrace();
    }





    File file2 = new File(imageFile2);
    FileInputStream fis2 = null;
    try {
        fis2 = new FileInputStream(imageFile2);
    } catch (FileNotFoundException e2) {
        // TODO Auto-generated catch block
        e2.printStackTrace();
    }



    BufferedImage oimage1 = ImageIO.read(file1);
    BufferedImage oimage2 = ImageIO.read(file2);


    ByteArrayOutputStream baos1=new ByteArrayOutputStream();


    byte[] buf1 = new byte[1024];

    try {
        for (int readNum; (readNum = fis1.read(buf1)) != -1;) {

            baos1.write(buf1, 0, readNum); 

        }
    } catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }


    ByteArrayOutputStream baos2=new ByteArrayOutputStream();


    byte[] buf2 = new byte[1024];

    try {
        for (int readNum; (readNum = fis2.read(buf1)) != -1;) {

            baos2.write(buf2, 0, readNum); 

        }
    } catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }

    final byte[] imageInByte1 = baos1.toByteArray();
    final int size1 = imageInByte1.length;


    final byte[] imageInByte2 = baos2.toByteArray();
    final int size2 = imageInByte2.length;



    int width1 = oimage1.getWidth();
    int height1 = oimage1.getHeight();
    int pixel1 = 0; 
    int red1,green1,blue1;

    int width2 = oimage2.getWidth();
    int height2 = oimage2.getHeight();
    int pixel2=0,red2,green2,blue2;



    final BufferedImage newimg1 = new BufferedImage(width1, height1, BufferedImage.TYPE_INT_ARGB);
    final BufferedImage newimg2 = new BufferedImage(width2, height2, BufferedImage.TYPE_INT_ARGB);

    for (int i = 0; i < width1; i++)
        for (int j = 0; j < height1; j++) {
            //scan through each pixel
            pixel1 = oimage1.getRGB(i, j);
            pixel2 = oimage2.getRGB(i, j);

        //for red

        String redpix1=Integer.toBinaryString(pixel1);  

        String binaryred1 = redpix1.substring(20,23);

        String redpix2=Integer.toBinaryString(pixel2);

         String binaryred2=redpix2.substring(20,23);

        String newred= binaryred1 + binaryred2;


        //for green
        String greenpix1=Integer.toBinaryString(pixel1);


        String binarygreen1=greenpix1.substring(12,15);

        String greenpix2=Integer.toBinaryString(pixel2);    
        String binarygreen2=greenpix2.substring(12,15);

        String newgreen= binarygreen1 + binarygreen2;


      //for blue
        String bluepix1=Integer.toBinaryString(pixel1); 


        String binaryblue1=bluepix1.substring(4,7);

        String bluepix2=Integer.toBinaryString(pixel2); 
        String binaryblue2=bluepix2.substring(4,7);

        String newblue= binaryblue1 + binaryblue2;

        //combining the new values
        String spixel=newred +newgreen + newblue;
        int newpixel = Integer.parseInt(spixel);

        newimg2.setRGB(i,j,newpixel);

        }   


    JFrame f =new JFrame();
     f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     f.getContentPane().add(new JLabel(new ImageIcon(newimg2)));
     f.pack();
    f.setLocationRelativeTo(null);
    f.setVisible(true);

    }                               
}

The size of 1.jpg is greater than size of 2.jpg. Can this code be modified to get output? or is any another easy way to embed the image?

Answer 1

The error message isn’t very explanatory. The NumberFormatExceptiondocumentation isn’t either in this case. It says:

Thrown to indicate that the application has attempted to convert a string to one of the numeric types, but that the string does not have the appropriate format.

What happens is an int overflow. The largest int you can have is 2 147 483 647 (10 digits), so 10010101101111111 (17 digits after I removed the leading 0) is way too large. This problem shows as a NumberFormatException.

If you intended that to be a binary number, use Integer.parseInt(spixel, 2) to indicate radix 2 (that is, binary). Then you should be able to parse it since up to 31 binary digits fit in an ìnt (not 32 because it’s signed, so there’s a sign bit).

There is a similar question to this one: What is a NumberFormatException and how can I fix it? However, while the accepted answer to that one does mention overflow (pretty deep down in the answer), it doesn’t cover trying to parse a string with the wrong radix. Still you may want to read through the question and answers and learn.