AWT-EventQueue-0" java.lang.NullPointerException

[justride]

Any idea why _mgr is null when I attempt to call openConnection()? It gets instantialed in the GUI constructor?

public class UTFSimulatorGUI extends JFrame implements ActionListener {

    UTFConnectionManager _mgr = null;
        
    public UTFSimulatorGUI() {
        UTFConnectionManager _mgr = new UTFConnectionManager();
    }
    
    private void openConnection(){
        System.out.println("Made it here");
	_mgr.openConnection();
    }
    
    public void actionPerformed(ActionEvent event) {
        Object source = event.getSource();
        if (source == _openSocket) {
            openConnection();
        }
    }
    

    private class UTFConnectionManager {
        public UTFConnectionManager() {
            super();
        }
        
        private void openConnection() {
            // I NEVER GET HERE
	    updateGUIStatus("OPENING CONNECTION");
        }
        
}

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at com.gtech.simulator.UTFSimulatorGUI.openConnection(UTFSimulatorGUI.java:60)
at com.gtech.simulator.UTFSimulatorGUI.actionPerformed(UTFSimulatorGUI.java:227)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1849)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2169)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:420)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:234)
at java.awt.Component.processMouseEvent(Component.java:5488)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3126)
at java.awt.Component.processEvent(Component.java:5253)
at java.awt.Container.processEvent(Container.java:1966)
at java.awt.Component.dispatchEventImpl(Component.java:3955)
at java.awt.Container.dispatchEventImpl(Container.java:2024)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3892)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
at java.awt.Container.dispatchEventImpl(Container.java:2010)
at java.awt.Window.dispatchEventImpl(Window.java:1774)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)

 

[justride]

perfect example why one should not code at 11pm while after working all day. sorry for the stupidity.

fix...

 UTFConnectionManager _mgr;
        
    public UTFSimulatorGUI() {
     _mgr = new UTFConnectionManager();

i dont know how i missed that.

 

[Diancecht]

I don't think it's stupid, I'd include that error in the hardest level to find.

I've been stumped for hours with these kind of errors, usually until someone that has no idea of what are you doing comes and says: "What are you doing?"

Cheers,
Dian