Re: heap memory issue, related with garbage collection

Eric Sosman <esosman@comcast-dot-net.invalid>
Fri, 21 Nov 2014 11:49:53 -0500
On 11/21/2014 11:41 AM, John wrote:


My standalone Java program displays a series of PNG files in a JFrame. Those PNG files were screen shots captured earlier with several seconds interval. There are hundreds of those PNG files.

The code is like:

     //the method below is repeated called with some interval: displayPic(++count);
     //so the PNG files are displayed one by one without stop -- like viewing a movie. The only problem is that after displaying about 100 PNG files, out of heap memory error occurs. If I increase heap memory: java -jar -Xmx2024m myJar.jar /pngFolder/
    //I can play more PNG files, but the error still happen eventually. I hope I can do some garbage collection to really solve the problem. Thank you.

     private void displayPic(final int picCount)

         String pngFileNameWithPath = xxx; //get PNG file name based on int picCount

         final ImageIcon imageIcon = new ImageIcon(pngFileNameWithPath);

         final JLabel picLabel = new JLabel();

         final JPanel picPanel = new JPanel();

         _jPanel.add(picPanel, BorderLayout.CENTER);




     You keep adding image after image to the same (?) JPanel and
then to the same (?) JFrame; do you ever remove any of them, or
do you just let them pile atop each other to a dizzying height?

     (I'm not 100% sure of this diagnosis, because you've not shown
what _jPanel and _jFrame are, nor how they are managed. One thing
looks odd, though it probably has nothing to do with your memory
issue: Shouldn't you call _jFrame.pack() after changing its content?)

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