Icon icon = new ImageIcon(getClass().getResource( "/img/icon.gif" ) );
aButton = new JButton("Its a button", icon);
Is there some kind of method that can stop an animated from playing? 
I was thinking of assigning a static jpg of the gif, then when I hover, assign the animated gif, but I don't think there is an event for taking off mouse in MouseMotionListener so I can load back the static jpg.
The gif loops in the button, however, if I hover over it, it disappears.
How can I make the gif static if my mouse cursor is not on the button?
If I use MouseMotionListener, does it fire an event if I take off my mouse?
@Override
public void mouseMoved(MouseEvent e) {
//play the gif
//if I take mouse off, call some method to stop playing animated gif
}
@Override
public void mouseDragged(MouseEvent e) {
}
    See:
setIcon(Icon)setDisabledIcon(Icon)setPressedIcon(Icon)setRolloverIcon(Icon)setSelectedIcon(Icon)
No need for setting an explicit mouse listener, the changeover happens automatically.
E.G.  In this example I did not add a MediaTracker so popped the image into a label to allow for load time.  The end user is the ImageObserver (wait till you see it spin before dismissing the first dialog).
import java.awt.*;
import java.awt.image.BufferedImage;
import java.net.URL;
import javax.swing.*;
public class ImageSwapOnButton {
    public static void main( String[] args ) throws Exception {
        URL url = new URL("http://1point1c.org/gif/thum/plnttm.gif");
        Image image = Toolkit.getDefaultToolkit().createImage(url);
        ImageIcon spinIcon = new ImageIcon(image);
        JOptionPane.showMessageDialog(null, new JLabel(spinIcon));
        // create a static version of this icon
        BufferedImage bi = new BufferedImage(150,150,BufferedImage.TYPE_INT_ARGB);
        Graphics g = bi.getGraphics();
        g.drawImage(image,0,0,null);
        g.dispose();
        ImageIcon staticIcon = new ImageIcon(bi);
        JButton button = new JButton(staticIcon);
        button.setRolloverIcon(spinIcon);
        JOptionPane.showMessageDialog(null, button);
    }
}
Also, don't make the static image as JPEG. A JPEG is lossy and does not support transparency. Either use a single frame GIF or a PNG.
button.setIcon(new ImageIcon("/*icon location*/"));
button.setRolloverIcon(new ImageIcon("/*icon location*/"
The Animated gif image will not get invisible when mouse pointer moves over the button.
来源:https://stackoverflow.com/questions/12874831/animated-gif-on-a-jbutton-play-it-when-mouse-is-hovered