Java - BufferedImage (ImageIO.Read) OutOfMemory Heap Space

Question

Ok, so I am getting an Out of Memory (Heap Space) error in my code, and I have figured out (with profiling) that the error is coming from the creation of images.

What I have is a class that creates an image into a smaller one, and then that class will be painted.

The problem is that if I want to load up 1000+ of these images into JPanels, I get to around 750 before it taps out, and I don't really want to extend the memory of java.

Heres the code:

class Foo extends JPanel{
private BufferedImage image;
private Image scaled;   
public Foo(String link){
    try{
        setPreferredSize(new Dimension(50,50));
        image = ImageIO.read(new URL(link)); //Cause for memory leak
        scaled= image.getScaledInstance(100, 140, BufferedImage.SCALE_FAST);
        image.flush();
                    //tried image = null; but did not help memory
    }
    catch(Exception e){}
}

public void paintComponent(Graphics g){
    super.paintComponent(g);
    g.drawImage(scaled, 5, 5, null);
}
}

So basically, is there a more efficient way to read a link into an image, or some how remove unnecessary memory?

Answer 1

我不确定这是否足够，但是您可以使用以下方法消除使用scaled的情况：

drawImage(Image img, int x, int y, int width, int height, ImageObserver observer) 

Answer 2

Know problem...

You probably don't need to re-read the full images each time.

I have implemented a similar feature. What I do is that I store snapshots of every image at a desired size + I include in the filename the timestamp of this snapshot so that I know if the snapshot is still up-to-date.

This does not solve your problem for the initial snapshot making but well for later uses.