Using Java to read image from file, and saving it to a different file

Question

I am trying to do the above, but each time, I keep getting the following errorjava.io.FileNotFoundException: file:\C:\Users\User\Desktop\Scrap\main\out\production\resources\ProfilePic\xas.png (The filename, directory name, or volume label syntax is incorrect)

Here's the function I used to do this

  private URL url = this.getClass().getResource("/ProfilePic");
  public final String PICTURE_DIRECTORY  = url.toString();


 public String createNewPicture (String path, String newPictureName) {
    int width = 12;
    int height = 12;
    BufferedImage bf = null;
    File f = null;
    String dst = PICTURE_DIRECTORY +"/"+newPictureName+".png";
    try{
        f = new File("F://a.jpg");
        bf = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);

        bf = ImageIO.read(f);
        System.out.println("read file successfully");


    } catch (Exception e) {
        System.out.println(e.getMessage());
    }

    try {
        dst = PICTURE_DIRECTORY +"/"+newPictureName+".png";
        new File (PICTURE_DIRECTORY, newPictureName+".png");
        f = new File(dst);
       ImageIO.write(bf, "png", f);
        //System.out.println("asaas " +dst);
    }
    catch (Exception e) {
        System.out.println(e.getMessage());
    }

    return dst;
}

Can someone please help me? Spent several hours trying to solve this but stuck. Thanks!

You don't need the line, bf = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB); You just get rid of it on the next line. Which line is causing the file not found? Also you cannot write to a resource like that. Your PICTURE_DIRECTORY is wrong. — matt
– matt, Commented Mar 18, 2018 at 9:28
The directory doesn't exist. There are several lines of redundant code here. — user207421
– user207421, Commented Mar 18, 2018 at 9:30
ImageIO is great when you want to display or modify images. For copying files, it's simply the wrong solution. Use Files.copy(...), see the Copying a File or Directory tutorial. — Harald K
– Harald K, Commented Mar 19, 2018 at 7:58

Harald K · Accepted Answer · 2018-03-19 15:01:26Z

1

The information you need is found in the error message:

java.io.FileNotFoundException: file:\C:\Users\User\Desktop\Scrap\main\out\production\resources\ProfilePic\xas.png (The filename, directory name, or volume label syntax is incorrect)

The problem in your code is found here:

private URL url = this.getClass().getResource("/ProfilePic");
public final String PICTURE_DIRECTORY  = url.toString();

A URL contains a protocol, "file" in your case. The URL class' toString() simply returns the full URL, including protocol. You now have variable PICTURE_DIRECTORY containing "file:/C:/...". This is not a valid path on any Windows OS.

If you really want to write to a resource (not recommended), you could do:

public final String PICTURE_DIRECTORY  = toFile(url).getAbsolutePath(); 

static private File toFile(final URL url) {
    try {
        return new File(url.toURI());
    }
    catch (URISyntaxException e) {
        throw new IllegalArgumentException(e);
    }
}

But note that a resource, as returned by Class..getResource(..), isn't always a file. It could just as well be an entry in a JAR (which you can't write to, in the same way as writing a file).

A better approach would probably be to use a directory relative to your users home directory, or other configured directory.

Finally, as I mentioned in the comments, using ImageIO for copying (image) files is usually the wrong solution. Instead, use Files.copy(...), as in the Copying a File or Directory tutorial.

edited Mar 19, 2018 at 15:01

answered Mar 19, 2018 at 13:39

Harald K

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1 Comment

gkhaos Over a year ago

in addition: this would work across the platforms, since java figures out how to translate it to the os-specific location

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