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POJavaFX - Label -- How to Access Class Member
 

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    <p>So my question is very simple. I can access class members <em>in a separate class</em> when they are a <code>String</code> rather than a <code>Label</code>, but I can't seem to, when they <em>are</em> <code>Label</code>. Using JDK 7u6 (w/ JavaFX 2.2).</p> <p>Simple examples. First one works, second one doesn't. <code>foo.label</code> can be assigned in the first example, but I get a NullPointer on the second example. Can anyone explain why <code>foo.label</code> is null in the second example below?</p> <p>UPDATE: I removed the @FXML annotations from my original question, because I didn't think they were necessary to the problem I was having. Also, see my comment on the <a href="https://stackoverflow.com/a/12468971/492404">answer by @jewelsea</a> ... Finally, I have added my FXML file, for completeness (at bottom of Q).</p> <p>This works:</p> <pre><code>// Example 1: public class SampleController implements Initializable { Foo foo = new Foo(); public void handleButtonAction(ActionEvent event) { System.out.println("You clicked me!"); foo.label = "Hello World!"; System.out.println(foo.label); } @Override public void initialize(URL url, ResourceBundle rb) { } } // Example 1 -- Foo.java: public class Foo { public String label; } </code></pre> <p>And this <em>does not</em> work:</p> <pre><code>// Example 2: public class SampleController implements Initializable { Foo foo = new Foo(); public void handleButtonAction(ActionEvent event) { System.out.println("You clicked me!"); foo.label.setText("Hello World!"); // gives NullPointer exception !! } @Override public void initialize(URL url, ResourceBundle rb) { } } // Example 2 -- Foo.java: import javafx.scene.control.Label; public class Foo { public Label label; } </code></pre> <p>Here is my FXML file, for either of the examples above:</p> <pre><code>&lt;AnchorPane id="AnchorPane" prefHeight="200" prefWidth="320" xmlns:fx="http://javafx.com/fxml" fx:controller="javafxapplication4.SampleController"&gt; &lt;children&gt; &lt;Button layoutX="126" layoutY="90" text="Click Me!" onAction="#handleButtonAction" fx:id="button" /&gt; &lt;Label layoutX="126" layoutY="120" minHeight="16" minWidth="69" fx:id="label" text="hey!" /&gt; &lt;/children&gt; &lt;/AnchorPane&gt; </code></pre>
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