[JGB-general] NullPointerException when calling method

[Ulrich R. <ulr...@gm...>]

Hi all!
I get a NullPointerException in the method getContextAccumulator (class
jgb.handlers.swing.MethodCallTagHandler).  The statement

MethodCall methodCall =
(MethodCall)tagContext.get(TagHandler.CURRENT_PARM_ACC_KEY);

returns null and causes the NullPointerException a few lines later. I'm a
JGB newbie, so maybe I am doing something very obvious wrong. I am trying to
dynamically populate a JComboBox when building it up, using the JComboBox
method setModel(ComboBoxModel aModel) setter. I have a method getBookComboBoxModel
in a class info.rueth.bp.DataSetter, which returns a ComboBoxModel object
(containing the elements I want to display in my JComboBox).

This is a snippet from my xml file:

...
<!-- Construct a DataSetter class -->
<object id="dataSetter" class="info.rueth.bp.gui.DataSetter">
    <constructor/>
</object>
...
<control>
...
    <combo id="bookChooser" reflabel="bookChooserLabel">
        <property name="model">
            <return>
                <methodCall refid="dataSetter"
method="getBookComboBoxModel"/>
            </return>
        </property>
    </combo>
...
</control>
...

Any hint is appreciated!
Thanks and regards
Ulrich

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