使用ImageIO打开图像后的Java文件操作

Question

I am working with Java and combine two images. I save the combined image and want to delete the overlay, but it seems there are still streams open. And i don't know which and how to close them.

f_overlay and f_image are both Files.

  // load source images
    BufferedImage image = null;
    BufferedImage overlay = null;
    try {
        log.debug(f_image.getAbsolutePath());
        log.debug(f_overlay.getAbsolutePath());
        image = ImageIO.read(f_image);
        overlay = ImageIO.read(f_overlay);
    } catch (IOException e) {
        log.error(e.getMessage());
    }

     // create the new image, canvas size is the max. of both image sizes
    int w = Math.max(image.getWidth(), overlay.getWidth());
    int h = Math.max(image.getHeight(), overlay.getHeight());
    BufferedImage combined = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);

    // paint both images, preserving the alpha channels
    Graphics g = combined.getGraphics();
    g.drawImage(image, 0, 0, null);
    g.drawImage(overlay, 0, 0, null);

    // Save as new image
    try {
        ImageIO.write(combined, "PNG", f_image);
    } catch (IOException e) {
        log.error(e.getMessage());
    }

    // we can delete the overlay now
    log.debug("Delete overlay: " + f_overlay.delete());

Are there any suggestions?

Answer 1

I can't see anything wrong in your code.

However, I would only delete the file f_overlay if the reading was successful. Important, after you call delete() on the file object, you must not use the object for anything else, so best is to assign f_overlay=null

boolean state = f_overlay.delete();
f_overlay=null;
log.debug("Delete ... "+state);