java缩放文件夹中的图像

Question

我正在尝试使用文件选择器调整图片大小。似乎所有的东西都是文件，但在添加到文件夹后我无法打开它

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();
}

} 之后我按下按钮将图像保存到文件夹中

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

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

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

但当我试图将其添加到文件夹中时，出现了一个错误

Answer 1

最后，我找到了在保存到文件夹之前缩放图像的方法。首先，我想为按钮添加一个侦听器，并使用文件选择器获取图像

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!");

            }
}

在我为另一个按钮添加侦听器之后，该按钮负责将图片添加到文件夹中。这是我的代码：

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

    } 

最后，让我们添加两个函数：

    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();
}

别忘了重要的方法

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;
}  




}

谢谢大家的帮助。我想对Mad程序员说声谢谢。你真是个天才