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POGetting a NullPointerException in my Swing Goose class
 

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  1. POGetting a NullPointerException in my Swing Goose class
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    <p>I think my <code>_holder</code> and/or <code>_gooseAction</code> is <code>null</code>.... Here are the relevant code/classes where <code>_holder</code> and <code>_gooseAction</code> are instantiated:</p> <h3>Goose.java</h3> <pre><code>public class Goose { //Goose class private ActionHolder _holder; private gooseAction _gooseAction; public Goose (JPanel container, GooseAction action, ActionHolder holder) { super(container); _holder = holder; _gooseAction = _holder.getAction(); _gooseAction = action; } public void react() { _gooseAction.stop(); _holder.getAction(); _gooseAction = _holder.getAction(); _gooseAction.setObjective(this); _gooseAction.start(); } </code></pre> <h3>ControlPanel.java</h3> <pre><code>public class ControlPanel { //top level class public ControlPanel() { super(); _holder = new ActionHolder(_moveAction); _drawingPanel = new DrawingPanel(_holder); _gooseAction = new GooseAction(); _doNothing = new StopBehavior(); _kingGoose = new FollowBehavior(_kingGoose); } private GooseAction _gooseAction; private ActionHolder _holder; public class ActionHolder { private GooseAction _GooseAction; public ActionHolder(GooseAction Action) { _gooseAction = Action; } public void setAction(GooseAction GooseAction) { _gooseAction = GooseAction; } public GooseAction getAction() { return _gooseAction.copy(); } } public class ActionButton extends JButton { public ActionButton(String string, boolean b, GooseAction action, ActionHolder holder) { super(string, b); _holder = holder; _gooseAction = action; } } private class ActionListener implements ChangeListener { public ActionListener(GooseAction action) { } public void stateChanged(ChangeEvent e) { _holder.setAction(_gooseAction); } } </code></pre>
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    1. USdurron597
    1. USSusie
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    1. COWhich line of code raises the exception?
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      1. POGetting a NullPointerException in my Swing Goose class
      1. USDavid Heffernan
    2. CODid you already use a debugger to find out where it breaks and what local variables are in your scope at that moment?
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      1. POGetting a NullPointerException in my Swing Goose class
      1. USMarnix
    3. COWhat's the exception you're getting? Let's see the stack trace of it.
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      1. UScorsiKa
 

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