How to delete a jar file after loading image files from it

Question

Hi,
How can I delete a jar file after some image files have been loaded? For example, say, I have "a.jar" which contains an image "a.gif" in the root directory of the c drive. I would like to get the image size and then delete the jar file. Here is the code snippet:
    URL url = new URL("jar:file:/C:\\a.jar!/a.gif");
    Icon icon = new ImageIcon(url);
    System.out.println("icon size ? " + icon.getIconHeight());
    File file = new File("c:\\a.jar");
    while(file.exists())
        file.delete();
        try
            Thread.sleep(100);
        catch (InterruptedException ignored)
    System.out.println("file deleted.");I get the image size correctly but just can not delete the jar file. Apparently the file handle is not released, but how to close it? Any hint will be appreciated.
Justin Jan

Answer 1

I am sure the URLConnection.defaultUseCaches is set before it is connected otherwise I should catch an IllegalStateException on conn.setUseCaches(false).
        try
            URL url = new URL("jar:file:/C:\\a.jar!/a.gif");           
         URLConnection conn = url.openConnection();
           conn.setDefaultUseCaches(false);
         conn.setUseCaches(false);
            Icon icon = new ImageIcon(url);
            System.out.println("icon size ? " + icon.getIconHeight());
            url.openConnection().getInputStream().close();
            System.gc();
         System.runFinalization();
            File file = new File("c:\\a.jar");
            while (file.exists())
                file.delete();
                try
                    Thread.sleep(10);
                catch (InterruptedException ignored)
            System.out.println("file deleted.");
        catch (Throwable t)
            t.printStackTrace();