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POIssue with JTextArea in Swing
 

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  1. POIssue with JTextArea in Swing
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    <p>I am having trouble updating a text area.</p> <p>I declare <code>textArea</code> in <code>gui.java</code>:</p> <pre><code>JTextArea textArea; </code></pre> <p>I start up the GUI..</p> <pre><code>public void startGUI() { // These are all essential GUI pieces JLabel jLabInstruction, jLaberror; JLabel copyright = new JLabel(""); JTextField uI = new JTextField(""); JTextArea textArea = new JTextArea(""); JButton jbtnSubmit; final JFrame jfrm = new JFrame("app name!"); jfrm.setLayout(new FlowLayout()); jfrm.setSize(300, 300); jfrm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); textArea = new JTextArea(5, 20); textArea.setEditable(false); textArea.setLineWrap(true); textArea.setWrapStyleWord(true); jLabInstruction = new JLabel("SYSTEM: Please type in a command: "); jbtnSubmit = new JButton("Submit"); jLaberror = new JLabel(""); textArea.setMargin(new Insets(10,10,10,10)); jfrm.add(jLaberror); jfrm.add(textArea); jfrm.add(jLabInstruction); jfrm.add(uI); jfrm.add(jbtnSubmit); jfrm.add(new JSeparator(SwingConstants.HORIZONTAL)); jfrm.add(copyright); jfrm.setVisible(true); } </code></pre> <p>And I have a method that writes to the <code>textArea</code> above:</p> <pre><code>public void writeToTextArea(String userInputText) { textArea.append("\nSYSTEM: " + userInputText); } </code></pre> <p>Also, in <code>tasks.java</code>, I am able to call on this last method:</p> <pre><code>gui.writeToTextArea("PROGRAM STARTED!"); </code></pre> <p>My problem is that the text area field is not updating. nothing is being inputted. I am thinking it is because it can't find what <code>textArea</code> is. I am getting an:</p> <pre><code>Exception in thread "main" java.lang.NullPointerException </code></pre>
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    1. PTQuestion
    1. USAndrew Thompson
    1. USdroidus
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    1. COFor better help sooner, post an [SSCCE](http://sscce.org/).
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      1. POIssue with JTextArea in Swing
      1. USAndrew Thompson
 

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