Java Development Tools

I am using the bottom-up web service generation in JDeveloper to create a WSDL for methods in a SessionBean. Is there any was to tell JDeveloper to make a WSDL element optional for one of my SessionBean's method parameters?

For example, if I have the following method,

public void getData(String param, String optParam)

How can I get the WSDL to be generated with the following element definitions?

<element name="getData">
<complexType>
<sequence>
<element name="param" type="string" nillable="true"/>
<element name="optParam" type="string" nillable="true" minOccurs="0"/>
</sequence>
</complexType>
</element>:

Thanks!