scale the image from the folder

Question

I am trying to resize the picture with file chooser. It seems everything is file, but I can't open it after adding in folder.

public void metodAddpath(String fullPath)  {

try {
                       File sourceFile = new File(fullPath);               
                     BufferedImage bufferedimage = ImageIO.read(sourceFile);
                     ByteArrayOutputStream os = new ByteArrayOutputStream();
                     ImageIO.write(bufferedimage, "jpg", os);
                      InputStream is = new ByteArrayInputStream(os.toByteArray());
        FileOutputStream fileOutputStream = new FileOutputStream(
                        sourceFile);

        int bufferSize;
        byte[] bufffer = new byte[512];

        while ((bufferSize = is.read(bufffer)) > 0) {
            fileOutputStream.write(bufffer, 0, bufferSize);
        }
        is.close();
        fileOutputStream.close();             

                    //scaleImage(bufferedimage, 220, 220);  

} catch(Exception e) {
    e.printStackTrace();
}

} After I push the button to save the image in folder.

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         

    Database base = new  Database();
   metodAddpath(jTextField1.getText());

    base.addPictureResource(jTextField1.getText());
}

But when I am trying to add it in folder, there is a mistake.

I'm just scratching my head over all the "buffers" and file I/O. Why not just use `ImageIO.write` to write the image directly to the file? — MadProgrammer, Nov 29 '18 at 23:01
*"It says thumbnail is not available. What is that mean?"* - You tell us, because the message makes no sense based on the available context — MadProgrammer, Nov 29 '18 at 23:02
I am a beginner in java. May you give me any example with ImageIO.write? I know it's hard to lead beginners, but I am trying my best to understand. — Dennis, Nov 29 '18 at 23:04
You open and read from fullPath, then try to create a new FileOutputStream with the same name. But that (existing) file is still open. — FredK, Nov 29 '18 at 23:06
@Dennis, for easy to use purpose you can use this image resizer library -> https://github.com/hkk595/Resizer — Jay Dangar, Nov 30 '18 at 04:57

score 1 · Accepted Answer · answered Nov 29 '18 at 23:06

I'm just going to come out and say it, none of this...

try {
    File sourceFile = new File(fullPath);               
    BufferedImage bufferedimage = ImageIO.read(sourceFile);
    ByteArrayOutputStream os = new ByteArrayOutputStream();
    ImageIO.write(bufferedimage, "jpg", os);
    InputStream is = new ByteArrayInputStream(os.toByteArray());
    FileOutputStream fileOutputStream = new FileOutputStream(
    sourceFile);

    int bufferSize;
    byte[] bufffer = new byte[512];

    while ((bufferSize = is.read(bufffer)) > 0) {
        fileOutputStream.write(bufffer, 0, bufferSize);
    }
    is.close();
    fileOutputStream.close();             

    //scaleImage(bufferedimage, 220, 220);  

} catch(Exception e) {
    e.printStackTrace();
}

makes sense.

You're reading the image, writing it to a ByteArrayOutputStream, piping that through a InputStream which you're then using to write the contents to another file via a FileOutputStream ... why?!

Something like...

File sourceFile = new File(fullPath);               
try {
    BufferedImage bufferedimage = ImageIO.read(sourceFile);

    //scaleImage(bufferedimage, 220, 220);  

    // Beware, this is overwriting the existing file
    try (FileOutputStream fileOutputStream = new FileOutputStream(sourceFile)) {
        ImageIO.write(bufferedimage, "jpg", fileOutputStream);
    }
} catch(Exception e) {
    e.printStackTrace();
}

would do the same job, is easier to read and probably more efficient...

I doubt this will answer you question, but it might reduce some of the confusion

Scaling an image is not an unusual job and has not only been asked before, is well documented. However, you might consider having a look at [Java: maintaining aspect ratio of JPanel background image](https://stackoverflow.com/questions/11959758/java-maintaining-aspect-ratio-of-jpanel-background-image/11959928#11959928) and [Quality of Image after resize very low — Java](https://stackoverflow.com/questions/14115950/quality-of-image-after-resize-very-low-java/14116752#14116752) for better implementations — MadProgrammer, Nov 29 '18 at 23:50
Thanks man, I will have a look at that example. I am appreciate your help. — Dennis, Nov 29 '18 at 23:57

score 0 · Answer 2 · answered Nov 30 '18 at 04:23

Finally, I found the way how to scale the image before saving in the folder. First I would like to add a listener for the button and get the image with file chooser.

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
   JFileChooser file = new JFileChooser();
            file.setCurrentDirectory(new File(System.getProperty("user.home")));

            FileNameExtensionFilter filter = new FileNameExtensionFilter("*.Images", "jpeg", "jpg", "png"); 
            file.addChoosableFileFilter(filter);
            int result = file.showSaveDialog(null);
            if(result ==JFileChooser.APPROVE_OPTION) {
                File selectedFile = file.getSelectedFile();
                //GET ABSOLUTE PATH OF PICTURES
                jTextField1.setText(selectedFile.getAbsolutePath());
                //addPicture.setText(selectedFile.getName()); 
                //GET NAME OF PICTURES
                //getPicName = selectedFile.getName();


            } else if(result == JFileChooser.CANCEL_OPTION) {
                System.out.println("File not found!");

            }
}

After I am adding a listener for another button that is responsible for adding a picture to the folder. Here is my code:

  private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        try{
   addPicture(jTextField1.getText());
          }catch(Exception e) {
    e.printStackTrace();
}

    }

And finally, let's add two functions:

    public void addPicture(String fullPath) throws IOException {
     File sourceFile = new File(fullPath);               
try {
    BufferedImage bufferedimage = ImageIO.read(sourceFile);
// add method scaleImage(bufferedimage, 220, 220) in ImageIO.write(scaleImage(bufferedimage, 220, 220), "jpg", fileOutputStream)  
    try (FileOutputStream fileOutputStream = new FileOutputStream("/my files/NetBeans IDE 8.2/NewDataBase/src/newdatabase/images/" + sourceFile.getName())) {
        ImageIO.write(scaleImage(bufferedimage, 220, 220), "jpg", fileOutputStream);
    }

} catch(Exception e) {
    e.printStackTrace();
}

Add don't forget about the important method

public BufferedImage scaleImage(BufferedImage img, int width, int height) {
int imgWidth = img.getWidth();
int imgHeight = img.getHeight();
if (imgWidth*height < imgHeight*width) {
    width = imgWidth*height/imgHeight;
} else {
    height = imgHeight*width/imgWidth;
}

BufferedImage newImage = new BufferedImage(width, height,
        BufferedImage.TYPE_INT_RGB);
Graphics2D g = newImage.createGraphics();
try {
    g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
            RenderingHints.VALUE_INTERPOLATION_BICUBIC);

    g.clearRect(0, 0, width, height);
    g.drawImage(img, 0, 0, width, height, null);
} 

finally {
    g.dispose();
}
return newImage;
}  




}

Thanks averyone for help. I would like to say thanks to MadProgrammer. You're a genius, man.

scale the image from the folder

2 Answers2