The above Java array is mapped to the following schema fragment:
The following example shows another form of XML schema representation and an XML schema instance:
So there is no "one way" to pass a String Array via DII. You are going to have to know the exact XML representation that the Web service is expecting. In the "literal" case you are going to have to use the complexType expected by the web service. In the "encoded" case you need to configure a serializer that produces a soapenc:Array that the web service's de-serializer can consume.
What is the XML Schema type definition for ns3:StringArray?
What is the style attribute in the operation binding?
What is the use attribute in the input binding?
Why are you using DII?
If you have a WSDL, use generated stubs or dynamics proxies. If you are using DII because you are dynamically discovering the WSDL then you will need to acquire a much, much deeper understanding of WSDL and XML Schema - Once you have that, usage of DII will seem much clearer.
At this point I think it may actually be easier to use SAAJ to create that SOAP request.