Exception when refreshing a comboBox with selected item in JavaFX (InvocationTargetException)

Question

I have a ComboBox which I initalize with a list of strings

ObservableList<String> list = FXCollections.observableArrayList();

for (String port : ports){
    list.add(port);
}

comboBoxSelectPort.setItems(list);

Then I select a item from the ComboBox, do some action and finally want to refresh the ComboBox with a empty list.

ObservableList<String> list = FXCollections.observableArrayList();
comboBoxSelectPort.setItems(list);

But every time a want to refresh the ComboBox I get following error. Maybe the problem is that some item is selected while I refresh?

Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
        at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
        at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
        at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
        at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
        at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
        at javafx.event.Event.fireEvent(Event.java:198)
        at javafx.scene.Node.fireEvent(Node.java:8411)
        at com.sun.javafx.scene.control.skin.ComboBoxListViewSkin.handleControlPropertyChanged(ComboBoxListViewSkin.java:179)
        at com.sun.javafx.scene.control.skin.BehaviorSkinBase.lambda$registerChangeListener$61(BehaviorSkinBase.java:197)
        at com.sun.javafx.scene.control.MultiplePropertyChangeListenerHandler$1.changed(MultiplePropertyChangeListenerHandler.java:55)
        at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:89)
        at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361)
        at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
        at javafx.beans.property.ObjectPropertyBase.fireValueChangedEvent(ObjectPropertyBase.java:105)
        at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
        at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146)
        at javafx.scene.control.ComboBoxBase.setValue(ComboBoxBase.java:150)
        at javafx.scene.control.ComboBox.updateValue(ComboBox.java:463)
        at javafx.scene.control.ComboBox.access$200(ComboBox.java:192)
        at javafx.scene.control.ComboBox$3.changed(ComboBox.java:446)
        at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361)
        at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
        at javafx.beans.property.ReadOnlyObjectWrapper$ReadOnlyPropertyImpl.fireValueChangedEvent(ReadOnlyObjectWrapper.java:176)
        at javafx.beans.property.ReadOnlyObjectWrapper.fireValueChangedEvent(ReadOnlyObjectWrapper.java:142)
        at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
        at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146)
        at javafx.scene.control.SelectionModel.setSelectedItem(SelectionModel.java:102)
        at javafx.scene.control.ComboBox$ComboBoxSelectionModel.lambda$new$154(ComboBox.java:494)
        at com.sun.javafx.binding.ExpressionHelper$SingleInvalidation.fireValueChangedEvent(ExpressionHelper.java:137)
        at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
        at javafx.beans.property.ReadOnlyIntegerWrapper$ReadOnlyPropertyImpl.fireValueChangedEvent(ReadOnlyIntegerWrapper.java:176)
        at javafx.beans.property.ReadOnlyIntegerWrapper.fireValueChangedEvent(ReadOnlyIntegerWrapper.java:142)
        at javafx.beans.property.IntegerPropertyBase.markInvalid(IntegerPropertyBase.java:113)
        at javafx.beans.property.IntegerPropertyBase.set(IntegerPropertyBase.java:147)
        at javafx.scene.control.SelectionModel.setSelectedIndex(SelectionModel.java:68)
        at javafx.scene.control.ComboBox$ComboBoxSelectionModel.updateItemsObserver(ComboBox.java:578)
        at javafx.scene.control.ComboBox$ComboBoxSelectionModel.access$400(ComboBox.java:482)
        at javafx.scene.control.ComboBox$ComboBoxSelectionModel$1.invalidated(ComboBox.java:511)
        at javafx.beans.WeakInvalidationListener.invalidated(WeakInvalidationListener.java:83)
        at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:349)
        at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
        at javafx.beans.property.ObjectPropertyBase.fireValueChangedEvent(ObjectPropertyBase.java:105)
        at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
        at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146)
        at javafx.scene.control.ComboBox.setItems(ComboBox.java:286)
        at de.control.GrblSender.setPorts(GrblSender.java:90)
        at de.control.Controller.handleButtonDisconnect(Controller.java:397)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
        at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
        at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
        at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
        at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
        at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
        at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
        at javafx.event.Event.fireEvent(Event.java:198)
        at javafx.scene.Node.fireEvent(Node.java:8411)
        at javafx.scene.control.Button.fire(Button.java:185)
        at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
        at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
        at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
        at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
        at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
        at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
        at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
        at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
        at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
        at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
        at javafx.event.Event.fireEvent(Event.java:198)
        at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
        at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
        at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
        at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:352)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
        at java.security.AccessController.doPrivileged(Native Method)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:388)
        at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
        at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
        at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
        at com.sun.glass.ui.View.notifyMouse(View.java:937)
        at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
        at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
        at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
        at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
        at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
        ... 119 more
Caused by: java.lang.NullPointerException
        at de.control.Controller.handleComboBoxSelectPort(Controller.java:68)
        ... 129 more

Is there a reason you want to make a new list instead of clearing the old one? ObservableList has a remove method you would do `list.remove(0, list.size());` — dustinroepsch, Apr 08 '16 at 19:20
There is no reason. I changed it, but obvious no effect on the exception. — Luke, Apr 08 '16 at 19:36
You have a NullPointerException at line 68 in Controller class. — ItachiUchiha, Apr 08 '16 at 19:39
This question http://stackoverflow.com/questions/3988788/what-is-a-stack-trace-and-how-can-i-use-it-to-debug-my-application-errors is useful reading for learning how to decipher the stack trace. — James_D, Apr 08 '16 at 19:47

Luke · Answer 1 · 2016-04-08T20:11:49.653

From CONTROLLER Class

@FXML
public void handleComboBoxSelectPort(ActionEvent event) {

    String selectedPort = comboBoxSelectPort.getValue();
    imageViewPreloader.setStyle("-fx-opacity: 1");

    if( !selectedPort.isEmpty() ) {                         // LINE 68
        try { grblSender.openPort(selectedPort); }
        catch(Exception e){}
    }
}

I replaced line 68 with

if( selectedPort != null && !selectedPort.isEmpty() ) {

which prevented the NullPointerException and solved my problem!

Exception when refreshing a comboBox with selected item in JavaFX (InvocationTargetException)

1 Answers1