paint()不能绘制gif,但png可以吗?

我正在使用JLabel试图在上面绘制一个动画gif图像。我可以使用构造函数 new JLabel(new ImageIcon(FML.class.getResource("giphy.gif"))); (使用java 1.8)

Like this one 但在这种情况下,这似乎不起作用。

我应该注意到,课堂上几乎没有其他事情发生,这是一个简单的JPanel。

    import java.awt.EventQueue;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class FML {

    public static void main(String[] args) {
        new FML();
    }

    public FML() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.getContentPane().setLayout(new FlowLayout());
                frame.getContentPane().add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private ImageIcon animatedGif;

        public TestPane() {
            setLayout(new GridBagLayout());
            JButton btn = new JButton(new ImageIcon(FML.class.getResource("FmDxW.png")));
            btn.setSize(50, 50);
            btn.setRolloverEnabled(true);
            animatedGif = new ImageIcon(FML.class.getResource("giphy.gif"));
            btn.setRolloverIcon(animatedGif);
            add(btn);

            btn.addMouseListener(new MouseAdapter() {

                @Override
                public void mouseEntered(MouseEvent e) {
                    animatedGif.getImage().flush();
                }

            });

            //I need this
            final ImageIcon image = new ImageIcon(FML.class.getResource("giphy.gif"));

            //To render over this
            final ImageIcon image2 = new ImageIcon(FML.class.getResource("fmDxW.png"));


            //I'm not understanding why I can add the gif into the constructor but the paint method fails.
            JLabel label = new JLabel(image) {
                @Override
                public void paint(Graphics g) {
                    super.paint(g);
                    g.drawImage(image2.getImage(), 64, 64, this);
                }
            };
            //setSize because I want to be 100% sure that it's loading the correct size.
            //Removing it doesn't affect the problem at hand.
            label.setSize(64, 64);
            add(label);
        }
    }
}