Message d'erreur nullpointerexception
Bonjour je réalise un petit programme pour apprendre java mais voila j ai un petit message d'erreur :
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at exemple8$MyActionListener.actionPerformed(exemple8.java:39)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Et voici mon programme
Code:
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| import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class exemple8
{
private int count = 0;
private JLabel label;
public exemple8()
{
JFrame frame = new JFrame("exemple");
JButton button = new JButton("clic clic");
button.addActionListener(new MyActionListener());
JLabel label = new JLabel("0");
JPanel pane = new JPanel();
pane.add(button);
pane.add(label);
frame.getContentPane().add(pane, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);
}
/* on peut écrire une class à l'intérieur d'une autre, */
/* utilisée uniquement dans la classe englobante. */
private class MyActionListener implements ActionListener
{
public void actionPerformed(ActionEvent event)
{
count++;
label.setText(Integer.toString(count));
}
}
public static void main(String[] args)
{
new exemple8();
}
} |
Et apparement l'erreur viendrait de la ligne 39 soit :
label.setText(Integer.toString(count));
Vraiment besoins d aide svpp