title: change text label Javafx
body: <p><strong>I have problem when I change the content of label the JVM throw this Exception this is the code:</strong></p>
  
  <pre><code>labelVers.setText(copy.get(i).getAbsolutePath().toString());
  
  labelNom.setText(copy.get(i).getName());
  </code></pre>
  
  <p><strong>this is Exception:</strong></p>
  
  <pre><code>Exception in thread "Thread-4" java.lang.IllegalStateException: Not on FX application thread; currentThread = Thread-4
      at com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:229)
      at com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:423)
      at javafx.scene.Parent$2.onProposedChange(Parent.java:367)
      at com.sun.javafx.collections.VetoableListDecorator.setAll(VetoableListDecorator.java:113)
      at com.sun.javafx.collections.VetoableListDecorator.setAll(VetoableListDecorator.java:108)
      at com.sun.javafx.scene.control.skin.LabeledSkinBase.updateChildren(LabeledSkinBase.java:575)
      at com.sun.javafx.scene.control.skin.LabeledSkinBase.handleControlPropertyChanged(LabeledSkinBase.java:204)
      at com.sun.javafx.scene.control.skin.LabelSkin.handleControlPropertyChanged(LabelSkin.java:49)
      at com.sun.javafx.scene.control.skin.BehaviorSkinBase.lambda$registerChangeListener$61(BehaviorSkinBase.java:197)
      at com.sun.javafx.scene.control.MultiplePropertyChangeListenerHandler$1.changed(MultiplePropertyChangeListenerHandler.java:55)
      at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:89)
      at com.sun.javafx.binding.ExpressionHelper$SingleChange.fireValueChangedEvent(ExpressionHelper.java:182)
      at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
      at javafx.beans.property.StringPropertyBase.fireValueChangedEvent(StringPropertyBase.java:103)
      at javafx.beans.property.StringPropertyBase.markInvalid(StringPropertyBase.java:110)
      at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:144)
      at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:49)
      at javafx.beans.property.StringProperty.setValue(StringProperty.java:65)
      at javafx.scene.control.Labeled.setText(Labeled.java:145)
      at sample.Controller.OnStart(Controller.java:37)
      at sample.Controller$1.run(Controller.java:84)
  </code></pre>