找不到ImageIO错误文件

Question

i am trying to load a jpg image on a canvas where the Line2D line1 is being drawn at. I wanted to overlay the image under the line because i am trying to do a symmetry math question online.

I keep getting the exception error file not found but i have placed my image in the main directory in the java file itself.

Any one can help??

public SliderControlPaintLine() {
JPanel controlPanel = new JPanel();
controlPanel.setLayout(new GridLayout(2,2));
getContentPane().add(controlPanel, BorderLayout.NORTH);

JLabel label1 = new JLabel("Translate(dx,dy): ");
JLabel label2 = new JLabel("Rotate(Theta,ox,oy): ");
JLabel label3 = new JLabel("Scale(sx,sy)x10E-2:");

controlPanel.add(label1);

slider1 = createSlider(controlPanel, JSlider.HORIZONTAL, 0, 300, 150, 100, 50);
slider2 = createSlider(controlPanel, JSlider.HORIZONTAL, 0, 300, 150, 100, 50);

controlPanel.add(label2);

slider3 = createSlider(controlPanel, JSlider.HORIZONTAL, 0, 360, 0, 90, 45);

getContentPane().add(canvas);

try {
    image = ImageIO.read(new FileInputStream("symmetry.jpg"));
} catch (FileNotFoundException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

setSize(800,700);
setVisible(true);
}

I am showing where i declared and initialized the ImageIO.

  class DrawingCanvas extends Canvas {
public DrawingCanvas() {
  setSize(300, 300);
}

public void paint(Graphics g) {


  super.paint(g);   
  g.drawImage(image, 0, 0, this);
  Graphics2D g2D = (Graphics2D) g;

  g2D.translate(transX, transY);
  g2D.rotate(rotateTheta, rotateX, rotateY);
  g2D.scale(scaleX, scaleY);
  BasicStroke stroke = new BasicStroke(width);
  g2D.setStroke(stroke);
  Line2D line1 = new Line2D.Float(100f, 200f, 500f, 200f);
  g2D.draw(line1);
}
}

Answer 1

Make sure that your current working directory is the one with the image file. You can get the current directory by calling the following:

System.getProperty("user.dir")

You could be using absolute path too to make sure the correct path. You can get your program's path by calling:

 MyClass.class.getProtectionDomain().getCodeSource().getLocation().getPath()

Answer 2

Which IDE do you use? You need to place your symmetry.jpg file into your working directory. This is mostly configured in the runtime settings.

Answer 3

try {
        image = ImageIO.read(new File(getClass().getResource("symmetry.jpg").toURI()));
    } catch (URISyntaxException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

Thanks guys for all your comment. I managed to use this to get the image to show. :)

Answer 4

Try

ImageIO.write(new BufferedImage(10, 10, BufferedImage.TYPE_3BYTE_BGR), "jpg", new File("symmetry2.jpg"));

and see where the file is written. That is where you have to place your symmetry.jpg